diff --git a/sandbox/Sandbox/Generated.cs b/sandbox/Sandbox/Generated.cs
index 64f68f84..9b5c623c 100644
--- a/sandbox/Sandbox/Generated.cs
+++ b/sandbox/Sandbox/Generated.cs
@@ -7,14 +7,11 @@
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace MessagePack.Resolvers
 {
-    using System;
-
     public class GeneratedResolver : global::MessagePack.IFormatterResolver
     {
         public static readonly global::MessagePack.IFormatterResolver Instance = new GeneratedResolver();
@@ -45,11 +42,11 @@ namespace MessagePack.Resolvers
 
     internal static class GeneratedResolverGetFormatterHelper
     {
-        private static readonly global::System.Collections.Generic.Dictionary<Type, int> lookup;
+        private static readonly global::System.Collections.Generic.Dictionary<global::System.Type, int> lookup;
 
         static GeneratedResolverGetFormatterHelper()
         {
-            lookup = new global::System.Collections.Generic.Dictionary<Type, int>(72)
+            lookup = new global::System.Collections.Generic.Dictionary<global::System.Type, int>(72)
             {
                 { typeof(global::GlobalMyEnum[,]), 0 },
                 { typeof(global::GlobalMyEnum[]), 1 },
@@ -126,7 +123,7 @@ namespace MessagePack.Resolvers
             };
         }
 
-        internal static object GetFormatter(Type t)
+        internal static object GetFormatter(global::System.Type t)
         {
             int key;
             if (!lookup.TryGetValue(t, out key))
@@ -220,7 +217,6 @@ namespace MessagePack.Resolvers
 #pragma warning restore 612
 
 #pragma warning restore SA1312 // Variable names should begin with lower-case letter
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1649 // File name should match first type name
 
 
@@ -233,24 +229,20 @@ namespace MessagePack.Resolvers
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1403 // File may only contain a single namespace
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace MessagePack.Formatters
 {
-    using System;
-    using System.Buffers;
-    using MessagePack;
 
     public sealed class GlobalMyEnumFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::GlobalMyEnum>
     {
-        public void Serialize(ref MessagePackWriter writer, global::GlobalMyEnum value, global::MessagePack.MessagePackSerializerOptions options)
+        public void Serialize(ref global::MessagePack.MessagePackWriter writer, global::GlobalMyEnum value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            writer.Write((Int32)value);
+            writer.Write((global::System.Int32)value);
         }
 
-        public global::GlobalMyEnum Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+        public global::GlobalMyEnum Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             return (global::GlobalMyEnum)reader.ReadInt32();
         }
@@ -262,7 +254,6 @@ namespace MessagePack.Formatters
 #pragma warning restore 618
 #pragma warning restore 612
 
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1403 // File may only contain a single namespace
 #pragma warning restore SA1649 // File name should match first type name
 
@@ -275,24 +266,20 @@ namespace MessagePack.Formatters
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1403 // File may only contain a single namespace
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace MessagePack.Formatters.SharedData
 {
-    using System;
-    using System.Buffers;
-    using MessagePack;
 
     public sealed class ByteEnumFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::SharedData.ByteEnum>
     {
-        public void Serialize(ref MessagePackWriter writer, global::SharedData.ByteEnum value, global::MessagePack.MessagePackSerializerOptions options)
+        public void Serialize(ref global::MessagePack.MessagePackWriter writer, global::SharedData.ByteEnum value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            writer.Write((Byte)value);
+            writer.Write((global::System.Byte)value);
         }
 
-        public global::SharedData.ByteEnum Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+        public global::SharedData.ByteEnum Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             return (global::SharedData.ByteEnum)reader.ReadByte();
         }
@@ -304,7 +291,6 @@ namespace MessagePack.Formatters.SharedData
 #pragma warning restore 618
 #pragma warning restore 612
 
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1403 // File may only contain a single namespace
 #pragma warning restore SA1649 // File name should match first type name
 
@@ -318,31 +304,25 @@ namespace MessagePack.Formatters.SharedData
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1403 // File may only contain a single namespace
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace MessagePack.Formatters
 {
-    using System;
-    using System.Buffers;
-    using System.Collections.Generic;
-    using MessagePack;
-
     public sealed class IMessageBodyFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::IMessageBody>
     {
-        private readonly Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>> typeToKeyAndJumpMap;
-        private readonly Dictionary<int, int> keyToJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>> typeToKeyAndJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<int, int> keyToJumpMap;
 
         public IMessageBodyFormatter()
         {
-            this.typeToKeyAndJumpMap = new Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>>(3, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
+            this.typeToKeyAndJumpMap = new global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>>(3, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
             {
-                { typeof(global::TextMessageBody).TypeHandle, new KeyValuePair<int, int>(10, 0) },
-                { typeof(global::StampMessageBody).TypeHandle, new KeyValuePair<int, int>(14, 1) },
-                { typeof(global::QuestMessageBody).TypeHandle, new KeyValuePair<int, int>(25, 2) },
+                { typeof(global::TextMessageBody).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(10, 0) },
+                { typeof(global::StampMessageBody).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(14, 1) },
+                { typeof(global::QuestMessageBody).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(25, 2) },
             };
-            this.keyToJumpMap = new Dictionary<int, int>(3)
+            this.keyToJumpMap = new global::System.Collections.Generic.Dictionary<int, int>(3)
             {
                 { 10, 0 },
                 { 14, 1 },
@@ -350,9 +330,9 @@ namespace MessagePack.Formatters
             };
         }
 
-        public void Serialize(ref MessagePackWriter writer, global::IMessageBody value, global::MessagePack.MessagePackSerializerOptions options)
+        public void Serialize(ref global::MessagePack.MessagePackWriter writer, global::IMessageBody value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            KeyValuePair<int, int> keyValuePair;
+            global::System.Collections.Generic.KeyValuePair<int, int> keyValuePair;
             if (value != null && this.typeToKeyAndJumpMap.TryGetValue(value.GetType().TypeHandle, out keyValuePair))
             {
                 writer.WriteArrayHeader(2);
@@ -378,7 +358,7 @@ namespace MessagePack.Formatters
             writer.WriteNil();
         }
 
-        public global::IMessageBody Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+        public global::IMessageBody Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             if (reader.TryReadNil())
             {
@@ -387,7 +367,7 @@ namespace MessagePack.Formatters
 
             if (reader.ReadArrayHeader() != 2)
             {
-                throw new InvalidOperationException("Invalid Union data was detected. Type:global::IMessageBody");
+                throw new global::System.InvalidOperationException("Invalid Union data was detected. Type:global::IMessageBody");
             }
 
             options.Security.DepthStep(ref reader);
@@ -428,7 +408,6 @@ namespace MessagePack.Formatters
 #pragma warning restore 618
 #pragma warning restore 612
 
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1403 // File may only contain a single namespace
 #pragma warning restore SA1649 // File name should match first type name
 
@@ -441,37 +420,31 @@ namespace MessagePack.Formatters
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1403 // File may only contain a single namespace
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace MessagePack.Formatters.SharedData
 {
-    using System;
-    using System.Buffers;
-    using System.Collections.Generic;
-    using MessagePack;
-
     public sealed class IIVersioningUnionFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::SharedData.IIVersioningUnion>
     {
-        private readonly Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>> typeToKeyAndJumpMap;
-        private readonly Dictionary<int, int> keyToJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>> typeToKeyAndJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<int, int> keyToJumpMap;
 
         public IIVersioningUnionFormatter()
         {
-            this.typeToKeyAndJumpMap = new Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>>(1, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
+            this.typeToKeyAndJumpMap = new global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>>(1, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
             {
-                { typeof(global::SharedData.MySubUnion1).TypeHandle, new KeyValuePair<int, int>(0, 0) },
+                { typeof(global::SharedData.MySubUnion1).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(0, 0) },
             };
-            this.keyToJumpMap = new Dictionary<int, int>(1)
+            this.keyToJumpMap = new global::System.Collections.Generic.Dictionary<int, int>(1)
             {
                 { 0, 0 },
             };
         }
 
-        public void Serialize(ref MessagePackWriter writer, global::SharedData.IIVersioningUnion value, global::MessagePack.MessagePackSerializerOptions options)
+        public void Serialize(ref global::MessagePack.MessagePackWriter writer, global::SharedData.IIVersioningUnion value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            KeyValuePair<int, int> keyValuePair;
+            global::System.Collections.Generic.KeyValuePair<int, int> keyValuePair;
             if (value != null && this.typeToKeyAndJumpMap.TryGetValue(value.GetType().TypeHandle, out keyValuePair))
             {
                 writer.WriteArrayHeader(2);
@@ -491,7 +464,7 @@ namespace MessagePack.Formatters.SharedData
             writer.WriteNil();
         }
 
-        public global::SharedData.IIVersioningUnion Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+        public global::SharedData.IIVersioningUnion Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             if (reader.TryReadNil())
             {
@@ -500,7 +473,7 @@ namespace MessagePack.Formatters.SharedData
 
             if (reader.ReadArrayHeader() != 2)
             {
-                throw new InvalidOperationException("Invalid Union data was detected. Type:global::SharedData.IIVersioningUnion");
+                throw new global::System.InvalidOperationException("Invalid Union data was detected. Type:global::SharedData.IIVersioningUnion");
             }
 
             options.Security.DepthStep(ref reader);
@@ -529,19 +502,19 @@ namespace MessagePack.Formatters.SharedData
 
     public sealed class IUnionCheckerFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::SharedData.IUnionChecker>
     {
-        private readonly Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>> typeToKeyAndJumpMap;
-        private readonly Dictionary<int, int> keyToJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>> typeToKeyAndJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<int, int> keyToJumpMap;
 
         public IUnionCheckerFormatter()
         {
-            this.typeToKeyAndJumpMap = new Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>>(4, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
+            this.typeToKeyAndJumpMap = new global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>>(4, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
             {
-                { typeof(global::SharedData.MySubUnion1).TypeHandle, new KeyValuePair<int, int>(0, 0) },
-                { typeof(global::SharedData.MySubUnion2).TypeHandle, new KeyValuePair<int, int>(1, 1) },
-                { typeof(global::SharedData.MySubUnion3).TypeHandle, new KeyValuePair<int, int>(2, 2) },
-                { typeof(global::SharedData.MySubUnion4).TypeHandle, new KeyValuePair<int, int>(3, 3) },
+                { typeof(global::SharedData.MySubUnion1).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(0, 0) },
+                { typeof(global::SharedData.MySubUnion2).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(1, 1) },
+                { typeof(global::SharedData.MySubUnion3).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(2, 2) },
+                { typeof(global::SharedData.MySubUnion4).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(3, 3) },
             };
-            this.keyToJumpMap = new Dictionary<int, int>(4)
+            this.keyToJumpMap = new global::System.Collections.Generic.Dictionary<int, int>(4)
             {
                 { 0, 0 },
                 { 1, 1 },
@@ -550,9 +523,9 @@ namespace MessagePack.Formatters.SharedData
             };
         }
 
-        public void Serialize(ref MessagePackWriter writer, global::SharedData.IUnionChecker value, global::MessagePack.MessagePackSerializerOptions options)
+        public void Serialize(ref global::MessagePack.MessagePackWriter writer, global::SharedData.IUnionChecker value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            KeyValuePair<int, int> keyValuePair;
+            global::System.Collections.Generic.KeyValuePair<int, int> keyValuePair;
             if (value != null && this.typeToKeyAndJumpMap.TryGetValue(value.GetType().TypeHandle, out keyValuePair))
             {
                 writer.WriteArrayHeader(2);
@@ -581,7 +554,7 @@ namespace MessagePack.Formatters.SharedData
             writer.WriteNil();
         }
 
-        public global::SharedData.IUnionChecker Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+        public global::SharedData.IUnionChecker Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             if (reader.TryReadNil())
             {
@@ -590,7 +563,7 @@ namespace MessagePack.Formatters.SharedData
 
             if (reader.ReadArrayHeader() != 2)
             {
-                throw new InvalidOperationException("Invalid Union data was detected. Type:global::SharedData.IUnionChecker");
+                throw new global::System.InvalidOperationException("Invalid Union data was detected. Type:global::SharedData.IUnionChecker");
             }
 
             options.Security.DepthStep(ref reader);
@@ -628,19 +601,19 @@ namespace MessagePack.Formatters.SharedData
 
     public sealed class IUnionChecker2Formatter : global::MessagePack.Formatters.IMessagePackFormatter<global::SharedData.IUnionChecker2>
     {
-        private readonly Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>> typeToKeyAndJumpMap;
-        private readonly Dictionary<int, int> keyToJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>> typeToKeyAndJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<int, int> keyToJumpMap;
 
         public IUnionChecker2Formatter()
         {
-            this.typeToKeyAndJumpMap = new Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>>(4, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
+            this.typeToKeyAndJumpMap = new global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>>(4, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
             {
-                { typeof(global::SharedData.MySubUnion2).TypeHandle, new KeyValuePair<int, int>(31, 0) },
-                { typeof(global::SharedData.MySubUnion3).TypeHandle, new KeyValuePair<int, int>(42, 1) },
-                { typeof(global::SharedData.MySubUnion4).TypeHandle, new KeyValuePair<int, int>(63, 2) },
-                { typeof(global::SharedData.MySubUnion1).TypeHandle, new KeyValuePair<int, int>(120, 3) },
+                { typeof(global::SharedData.MySubUnion2).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(31, 0) },
+                { typeof(global::SharedData.MySubUnion3).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(42, 1) },
+                { typeof(global::SharedData.MySubUnion4).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(63, 2) },
+                { typeof(global::SharedData.MySubUnion1).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(120, 3) },
             };
-            this.keyToJumpMap = new Dictionary<int, int>(4)
+            this.keyToJumpMap = new global::System.Collections.Generic.Dictionary<int, int>(4)
             {
                 { 31, 0 },
                 { 42, 1 },
@@ -649,9 +622,9 @@ namespace MessagePack.Formatters.SharedData
             };
         }
 
-        public void Serialize(ref MessagePackWriter writer, global::SharedData.IUnionChecker2 value, global::MessagePack.MessagePackSerializerOptions options)
+        public void Serialize(ref global::MessagePack.MessagePackWriter writer, global::SharedData.IUnionChecker2 value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            KeyValuePair<int, int> keyValuePair;
+            global::System.Collections.Generic.KeyValuePair<int, int> keyValuePair;
             if (value != null && this.typeToKeyAndJumpMap.TryGetValue(value.GetType().TypeHandle, out keyValuePair))
             {
                 writer.WriteArrayHeader(2);
@@ -680,7 +653,7 @@ namespace MessagePack.Formatters.SharedData
             writer.WriteNil();
         }
 
-        public global::SharedData.IUnionChecker2 Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+        public global::SharedData.IUnionChecker2 Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             if (reader.TryReadNil())
             {
@@ -689,7 +662,7 @@ namespace MessagePack.Formatters.SharedData
 
             if (reader.ReadArrayHeader() != 2)
             {
-                throw new InvalidOperationException("Invalid Union data was detected. Type:global::SharedData.IUnionChecker2");
+                throw new global::System.InvalidOperationException("Invalid Union data was detected. Type:global::SharedData.IUnionChecker2");
             }
 
             options.Security.DepthStep(ref reader);
@@ -727,26 +700,26 @@ namespace MessagePack.Formatters.SharedData
 
     public sealed class IUnionSampleFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::SharedData.IUnionSample>
     {
-        private readonly Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>> typeToKeyAndJumpMap;
-        private readonly Dictionary<int, int> keyToJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>> typeToKeyAndJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<int, int> keyToJumpMap;
 
         public IUnionSampleFormatter()
         {
-            this.typeToKeyAndJumpMap = new Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>>(2, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
+            this.typeToKeyAndJumpMap = new global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>>(2, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
             {
-                { typeof(global::SharedData.FooClass).TypeHandle, new KeyValuePair<int, int>(0, 0) },
-                { typeof(global::SharedData.BarClass).TypeHandle, new KeyValuePair<int, int>(100, 1) },
+                { typeof(global::SharedData.FooClass).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(0, 0) },
+                { typeof(global::SharedData.BarClass).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(100, 1) },
             };
-            this.keyToJumpMap = new Dictionary<int, int>(2)
+            this.keyToJumpMap = new global::System.Collections.Generic.Dictionary<int, int>(2)
             {
                 { 0, 0 },
                 { 100, 1 },
             };
         }
 
-        public void Serialize(ref MessagePackWriter writer, global::SharedData.IUnionSample value, global::MessagePack.MessagePackSerializerOptions options)
+        public void Serialize(ref global::MessagePack.MessagePackWriter writer, global::SharedData.IUnionSample value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            KeyValuePair<int, int> keyValuePair;
+            global::System.Collections.Generic.KeyValuePair<int, int> keyValuePair;
             if (value != null && this.typeToKeyAndJumpMap.TryGetValue(value.GetType().TypeHandle, out keyValuePair))
             {
                 writer.WriteArrayHeader(2);
@@ -769,7 +742,7 @@ namespace MessagePack.Formatters.SharedData
             writer.WriteNil();
         }
 
-        public global::SharedData.IUnionSample Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+        public global::SharedData.IUnionSample Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             if (reader.TryReadNil())
             {
@@ -778,7 +751,7 @@ namespace MessagePack.Formatters.SharedData
 
             if (reader.ReadArrayHeader() != 2)
             {
-                throw new InvalidOperationException("Invalid Union data was detected. Type:global::SharedData.IUnionSample");
+                throw new global::System.InvalidOperationException("Invalid Union data was detected. Type:global::SharedData.IUnionSample");
             }
 
             options.Security.DepthStep(ref reader);
@@ -810,26 +783,26 @@ namespace MessagePack.Formatters.SharedData
 
     public sealed class RootUnionTypeFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::SharedData.RootUnionType>
     {
-        private readonly Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>> typeToKeyAndJumpMap;
-        private readonly Dictionary<int, int> keyToJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>> typeToKeyAndJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<int, int> keyToJumpMap;
 
         public RootUnionTypeFormatter()
         {
-            this.typeToKeyAndJumpMap = new Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>>(2, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
+            this.typeToKeyAndJumpMap = new global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>>(2, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
             {
-                { typeof(global::SharedData.SubUnionType1).TypeHandle, new KeyValuePair<int, int>(0, 0) },
-                { typeof(global::SharedData.SubUnionType2).TypeHandle, new KeyValuePair<int, int>(1, 1) },
+                { typeof(global::SharedData.SubUnionType1).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(0, 0) },
+                { typeof(global::SharedData.SubUnionType2).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(1, 1) },
             };
-            this.keyToJumpMap = new Dictionary<int, int>(2)
+            this.keyToJumpMap = new global::System.Collections.Generic.Dictionary<int, int>(2)
             {
                 { 0, 0 },
                 { 1, 1 },
             };
         }
 
-        public void Serialize(ref MessagePackWriter writer, global::SharedData.RootUnionType value, global::MessagePack.MessagePackSerializerOptions options)
+        public void Serialize(ref global::MessagePack.MessagePackWriter writer, global::SharedData.RootUnionType value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            KeyValuePair<int, int> keyValuePair;
+            global::System.Collections.Generic.KeyValuePair<int, int> keyValuePair;
             if (value != null && this.typeToKeyAndJumpMap.TryGetValue(value.GetType().TypeHandle, out keyValuePair))
             {
                 writer.WriteArrayHeader(2);
@@ -852,7 +825,7 @@ namespace MessagePack.Formatters.SharedData
             writer.WriteNil();
         }
 
-        public global::SharedData.RootUnionType Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+        public global::SharedData.RootUnionType Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             if (reader.TryReadNil())
             {
@@ -861,7 +834,7 @@ namespace MessagePack.Formatters.SharedData
 
             if (reader.ReadArrayHeader() != 2)
             {
-                throw new InvalidOperationException("Invalid Union data was detected. Type:global::SharedData.RootUnionType");
+                throw new global::System.InvalidOperationException("Invalid Union data was detected. Type:global::SharedData.RootUnionType");
             }
 
             options.Security.DepthStep(ref reader);
@@ -899,7 +872,6 @@ namespace MessagePack.Formatters.SharedData
 #pragma warning restore 618
 #pragma warning restore 612
 
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1403 // File may only contain a single namespace
 #pragma warning restore SA1649 // File name should match first type name
 
@@ -914,7 +886,6 @@ namespace MessagePack.Formatters.SharedData
 #pragma warning disable 168
 
 #pragma warning disable SA1129 // Do not use default value type constructor
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1309 // Field names should not begin with underscore
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1403 // File may only contain a single namespace
@@ -922,9 +893,6 @@ namespace MessagePack.Formatters.SharedData
 
 namespace MessagePack.Formatters.Abcdefg.Efcdigjl.Ateatatea.Hgfagfafgad
 {
-    using global::System.Buffers;
-    using global::MessagePack;
-
     public sealed class TnonodsfarnoiuAtatqagaFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::Abcdefg.Efcdigjl.Ateatatea.Hgfagfafgad.TnonodsfarnoiuAtatqaga>
     {
 
@@ -968,6 +936,7 @@ namespace MessagePack.Formatters.Abcdefg.Efcdigjl.Ateatatea.Hgfagfafgad
             return ____result;
         }
     }
+
 }
 
 #pragma warning restore 168
@@ -976,7 +945,6 @@ namespace MessagePack.Formatters.Abcdefg.Efcdigjl.Ateatatea.Hgfagfafgad
 #pragma warning restore 612
 
 #pragma warning restore SA1129 // Do not use default value type constructor
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1309 // Field names should not begin with underscore
 #pragma warning restore SA1312 // Variable names should begin with lower-case letter
 #pragma warning restore SA1403 // File may only contain a single namespace
@@ -992,7 +960,6 @@ namespace MessagePack.Formatters.Abcdefg.Efcdigjl.Ateatatea.Hgfagfafgad
 #pragma warning disable 168
 
 #pragma warning disable SA1129 // Do not use default value type constructor
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1309 // Field names should not begin with underscore
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1403 // File may only contain a single namespace
@@ -1000,9 +967,6 @@ namespace MessagePack.Formatters.Abcdefg.Efcdigjl.Ateatatea.Hgfagfafgad
 
 namespace MessagePack.Formatters
 {
-    using global::System.Buffers;
-    using global::MessagePack;
-
     public sealed class ArrayTestTestFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::ArrayTestTest>
     {
 
@@ -1016,13 +980,13 @@ namespace MessagePack.Formatters
 
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(7);
-            formatterResolver.GetFormatterWithVerify<int[]>().Serialize(ref writer, value.MyProperty0, options);
-            formatterResolver.GetFormatterWithVerify<int[,]>().Serialize(ref writer, value.MyProperty1, options);
-            formatterResolver.GetFormatterWithVerify<global::GlobalMyEnum[,]>().Serialize(ref writer, value.MyProperty2, options);
-            formatterResolver.GetFormatterWithVerify<int[,,]>().Serialize(ref writer, value.MyProperty3, options);
-            formatterResolver.GetFormatterWithVerify<int[,,,]>().Serialize(ref writer, value.MyProperty4, options);
-            formatterResolver.GetFormatterWithVerify<global::GlobalMyEnum[]>().Serialize(ref writer, value.MyProperty5, options);
-            formatterResolver.GetFormatterWithVerify<global::QuestMessageBody[]>().Serialize(ref writer, value.MyProperty6, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<int[]>(formatterResolver).Serialize(ref writer, value.MyProperty0, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<int[,]>(formatterResolver).Serialize(ref writer, value.MyProperty1, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::GlobalMyEnum[,]>(formatterResolver).Serialize(ref writer, value.MyProperty2, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<int[,,]>(formatterResolver).Serialize(ref writer, value.MyProperty3, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<int[,,,]>(formatterResolver).Serialize(ref writer, value.MyProperty4, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::GlobalMyEnum[]>(formatterResolver).Serialize(ref writer, value.MyProperty5, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::QuestMessageBody[]>(formatterResolver).Serialize(ref writer, value.MyProperty6, options);
         }
 
         public global::ArrayTestTest Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -1042,25 +1006,25 @@ namespace MessagePack.Formatters
                 switch (i)
                 {
                     case 0:
-                        ____result.MyProperty0 = formatterResolver.GetFormatterWithVerify<int[]>().Deserialize(ref reader, options);
+                        ____result.MyProperty0 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<int[]>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 1:
-                        ____result.MyProperty1 = formatterResolver.GetFormatterWithVerify<int[,]>().Deserialize(ref reader, options);
+                        ____result.MyProperty1 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<int[,]>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 2:
-                        ____result.MyProperty2 = formatterResolver.GetFormatterWithVerify<global::GlobalMyEnum[,]>().Deserialize(ref reader, options);
+                        ____result.MyProperty2 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::GlobalMyEnum[,]>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 3:
-                        ____result.MyProperty3 = formatterResolver.GetFormatterWithVerify<int[,,]>().Deserialize(ref reader, options);
+                        ____result.MyProperty3 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<int[,,]>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 4:
-                        ____result.MyProperty4 = formatterResolver.GetFormatterWithVerify<int[,,,]>().Deserialize(ref reader, options);
+                        ____result.MyProperty4 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<int[,,,]>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 5:
-                        ____result.MyProperty5 = formatterResolver.GetFormatterWithVerify<global::GlobalMyEnum[]>().Deserialize(ref reader, options);
+                        ____result.MyProperty5 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::GlobalMyEnum[]>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 6:
-                        ____result.MyProperty6 = formatterResolver.GetFormatterWithVerify<global::QuestMessageBody[]>().Deserialize(ref reader, options);
+                        ____result.MyProperty6 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::QuestMessageBody[]>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     default:
                         reader.Skip();
@@ -1132,8 +1096,8 @@ namespace MessagePack.Formatters
             writer.WriteArrayHeader(4);
             writer.Write(value.UserId);
             writer.Write(value.RoomId);
-            formatterResolver.GetFormatterWithVerify<global::System.DateTime>().Serialize(ref writer, value.PostTime, options);
-            formatterResolver.GetFormatterWithVerify<global::IMessageBody>().Serialize(ref writer, value.Body, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.DateTime>(formatterResolver).Serialize(ref writer, value.PostTime, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::IMessageBody>(formatterResolver).Serialize(ref writer, value.Body, options);
         }
 
         public global::Message Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -1159,10 +1123,10 @@ namespace MessagePack.Formatters
                         ____result.RoomId = reader.ReadInt32();
                         break;
                     case 2:
-                        ____result.PostTime = formatterResolver.GetFormatterWithVerify<global::System.DateTime>().Deserialize(ref reader, options);
+                        ____result.PostTime = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.DateTime>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 3:
-                        ____result.Body = formatterResolver.GetFormatterWithVerify<global::IMessageBody>().Deserialize(ref reader, options);
+                        ____result.Body = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::IMessageBody>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     default:
                         reader.Skip();
@@ -1234,7 +1198,7 @@ namespace MessagePack.Formatters
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(2);
             writer.Write(value.QuestId);
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.Text, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.Text, options);
         }
 
         public global::QuestMessageBody Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -1257,7 +1221,7 @@ namespace MessagePack.Formatters
                         ____result.QuestId = reader.ReadInt32();
                         break;
                     case 1:
-                        ____result.Text = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                        ____result.Text = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     default:
                         reader.Skip();
@@ -1327,7 +1291,7 @@ namespace MessagePack.Formatters
 
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(1);
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.Text, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.Text, options);
         }
 
         public global::TextMessageBody Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -1347,7 +1311,7 @@ namespace MessagePack.Formatters
                 switch (i)
                 {
                     case 0:
-                        ____result.Text = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                        ____result.Text = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     default:
                         reader.Skip();
@@ -1359,6 +1323,7 @@ namespace MessagePack.Formatters
             return ____result;
         }
     }
+
 }
 
 #pragma warning restore 168
@@ -1367,7 +1332,6 @@ namespace MessagePack.Formatters
 #pragma warning restore 612
 
 #pragma warning restore SA1129 // Do not use default value type constructor
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1309 // Field names should not begin with underscore
 #pragma warning restore SA1312 // Variable names should begin with lower-case letter
 #pragma warning restore SA1403 // File may only contain a single namespace
@@ -1383,7 +1347,6 @@ namespace MessagePack.Formatters
 #pragma warning disable 168
 
 #pragma warning disable SA1129 // Do not use default value type constructor
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1309 // Field names should not begin with underscore
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1403 // File may only contain a single namespace
@@ -1391,9 +1354,6 @@ namespace MessagePack.Formatters
 
 namespace MessagePack.Formatters
 {
-    using global::System.Buffers;
-    using global::MessagePack;
-
     public sealed class ComplexModelFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::ComplexModel>
     {
         // AdditionalProperty
@@ -1420,17 +1380,17 @@ namespace MessagePack.Formatters
             var formatterResolver = options.Resolver;
             writer.WriteMapHeader(6);
             writer.WriteRaw(GetSpan_AdditionalProperty());
-            formatterResolver.GetFormatterWithVerify<global::System.Collections.Generic.IDictionary<string, string>>().Serialize(ref writer, value.AdditionalProperty, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.Collections.Generic.IDictionary<string, string>>(formatterResolver).Serialize(ref writer, value.AdditionalProperty, options);
             writer.WriteRaw(GetSpan_CreatedOn());
-            formatterResolver.GetFormatterWithVerify<global::System.DateTimeOffset>().Serialize(ref writer, value.CreatedOn, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.DateTimeOffset>(formatterResolver).Serialize(ref writer, value.CreatedOn, options);
             writer.WriteRaw(GetSpan_Id());
-            formatterResolver.GetFormatterWithVerify<global::System.Guid>().Serialize(ref writer, value.Id, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.Guid>(formatterResolver).Serialize(ref writer, value.Id, options);
             writer.WriteRaw(GetSpan_Name());
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.Name, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.Name, options);
             writer.WriteRaw(GetSpan_UpdatedOn());
-            formatterResolver.GetFormatterWithVerify<global::System.DateTimeOffset>().Serialize(ref writer, value.UpdatedOn, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.DateTimeOffset>(formatterResolver).Serialize(ref writer, value.UpdatedOn, options);
             writer.WriteRaw(GetSpan_SimpleModels());
-            formatterResolver.GetFormatterWithVerify<global::System.Collections.Generic.IList<global::SimpleModel>>().Serialize(ref writer, value.SimpleModels, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.Collections.Generic.IList<global::SimpleModel>>(formatterResolver).Serialize(ref writer, value.SimpleModels, options);
         }
 
         public global::ComplexModel Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -1466,25 +1426,25 @@ namespace MessagePack.Formatters
                             case 5720808977192022595UL:
                                 if (stringKey[0] != 110) { goto FAIL; }
 
-                                ____result.CreatedOn = formatterResolver.GetFormatterWithVerify<global::System.DateTimeOffset>().Deserialize(ref reader, options);
+                                ____result.CreatedOn = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.DateTimeOffset>(formatterResolver).Deserialize(ref reader, options);
                                 continue;
 
                             case 5720808977191956565UL:
                                 if (stringKey[0] != 110) { goto FAIL; }
 
-                                ____result.UpdatedOn = formatterResolver.GetFormatterWithVerify<global::System.DateTimeOffset>().Deserialize(ref reader, options);
+                                ____result.UpdatedOn = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.DateTimeOffset>(formatterResolver).Deserialize(ref reader, options);
                                 continue;
 
                         }
                     case 2:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 25673UL) { goto FAIL; }
 
-                        ____result.Id = formatterResolver.GetFormatterWithVerify<global::System.Guid>().Deserialize(ref reader, options);
+                        ____result.Id = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.Guid>(formatterResolver).Deserialize(ref reader, options);
                         continue;
                     case 4:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 1701667150UL) { goto FAIL; }
 
-                        ____result.Name = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                        ____result.Name = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                         continue;
                     case 12:
                         if (!global::System.MemoryExtensions.SequenceEqual(stringKey, GetSpan_SimpleModels().Slice(1))) { goto FAIL; }
@@ -1528,13 +1488,13 @@ namespace MessagePack.Formatters
             writer.WriteRaw(GetSpan_Id());
             writer.Write(value.Id);
             writer.WriteRaw(GetSpan_Name());
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.Name, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.Name, options);
             writer.WriteRaw(GetSpan_CreatedOn());
-            formatterResolver.GetFormatterWithVerify<global::System.DateTime>().Serialize(ref writer, value.CreatedOn, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.DateTime>(formatterResolver).Serialize(ref writer, value.CreatedOn, options);
             writer.WriteRaw(GetSpan_Precision());
             writer.Write(value.Precision);
             writer.WriteRaw(GetSpan_Money());
-            formatterResolver.GetFormatterWithVerify<decimal>().Serialize(ref writer, value.Money, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<decimal>(formatterResolver).Serialize(ref writer, value.Money, options);
             writer.WriteRaw(GetSpan_Amount());
             writer.Write(value.Amount);
         }
@@ -1568,7 +1528,7 @@ namespace MessagePack.Formatters
                     case 4:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 1701667150UL) { goto FAIL; }
 
-                        ____result.Name = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                        ____result.Name = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                         continue;
                     case 9:
                         switch (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey))
@@ -1577,7 +1537,7 @@ namespace MessagePack.Formatters
                             case 5720808977192022595UL:
                                 if (stringKey[0] != 110) { goto FAIL; }
 
-                                ____result.CreatedOn = formatterResolver.GetFormatterWithVerify<global::System.DateTime>().Deserialize(ref reader, options);
+                                ____result.CreatedOn = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.DateTime>(formatterResolver).Deserialize(ref reader, options);
                                 continue;
 
                             case 8028074707240972880UL:
@@ -1590,7 +1550,7 @@ namespace MessagePack.Formatters
                     case 5:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 521392779085UL) { goto FAIL; }
 
-                        ____result.Money = formatterResolver.GetFormatterWithVerify<decimal>().Deserialize(ref reader, options);
+                        ____result.Money = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<decimal>(formatterResolver).Deserialize(ref reader, options);
                         continue;
                     case 6:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 128017765461313UL) { goto FAIL; }
@@ -1605,8 +1565,20 @@ namespace MessagePack.Formatters
             return ____result;
         }
     }
+
 }
 
+#pragma warning restore 168
+#pragma warning restore 414
+#pragma warning restore 618
+#pragma warning restore 612
+
+#pragma warning restore SA1129 // Do not use default value type constructor
+#pragma warning restore SA1309 // Field names should not begin with underscore
+#pragma warning restore SA1312 // Variable names should begin with lower-case letter
+#pragma warning restore SA1403 // File may only contain a single namespace
+#pragma warning restore SA1649 // File name should match first type name
+
 // <auto-generated>
 // THIS (.cs) FILE IS GENERATED BY MPC(MessagePack-CSharp). DO NOT CHANGE IT.
 // </auto-generated>
@@ -1617,7 +1589,6 @@ namespace MessagePack.Formatters
 #pragma warning disable 168
 
 #pragma warning disable SA1129 // Do not use default value type constructor
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1309 // Field names should not begin with underscore
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1403 // File may only contain a single namespace
@@ -1625,9 +1596,6 @@ namespace MessagePack.Formatters
 
 namespace MessagePack.Formatters.PerfBenchmarkDotNet
 {
-    using global::System.Buffers;
-    using global::MessagePack;
-
     public sealed class StringKeySerializerTargetFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::PerfBenchmarkDotNet.StringKeySerializerTarget>
     {
         // MyProperty1
@@ -1744,8 +1712,20 @@ namespace MessagePack.Formatters.PerfBenchmarkDotNet
             return ____result;
         }
     }
+
 }
 
+#pragma warning restore 168
+#pragma warning restore 414
+#pragma warning restore 618
+#pragma warning restore 612
+
+#pragma warning restore SA1129 // Do not use default value type constructor
+#pragma warning restore SA1309 // Field names should not begin with underscore
+#pragma warning restore SA1312 // Variable names should begin with lower-case letter
+#pragma warning restore SA1403 // File may only contain a single namespace
+#pragma warning restore SA1649 // File name should match first type name
+
 // <auto-generated>
 // THIS (.cs) FILE IS GENERATED BY MPC(MessagePack-CSharp). DO NOT CHANGE IT.
 // </auto-generated>
@@ -1756,7 +1736,6 @@ namespace MessagePack.Formatters.PerfBenchmarkDotNet
 #pragma warning disable 168
 
 #pragma warning disable SA1129 // Do not use default value type constructor
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1309 // Field names should not begin with underscore
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1403 // File may only contain a single namespace
@@ -1764,9 +1743,6 @@ namespace MessagePack.Formatters.PerfBenchmarkDotNet
 
 namespace MessagePack.Formatters.SharedData
 {
-    using global::System.Buffers;
-    using global::MessagePack;
-
     public sealed class ArrayOptimizeClassFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::SharedData.ArrayOptimizeClass>
     {
 
@@ -1884,7 +1860,7 @@ namespace MessagePack.Formatters.SharedData
 
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(1);
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.OPQ, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.OPQ, options);
         }
 
         public global::SharedData.BarClass Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -1904,7 +1880,7 @@ namespace MessagePack.Formatters.SharedData
                 switch (i)
                 {
                     case 0:
-                        ____result.OPQ = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                        ____result.OPQ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     default:
                         reader.Skip();
@@ -2026,8 +2002,8 @@ namespace MessagePack.Formatters.SharedData
             writer.WriteArrayHeader(4);
             writer.Write(value.Prop1);
             writer.Write(value.Prop2);
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.Prop3, options);
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.Prop4, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.Prop3, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.Prop4, options);
         }
 
         public global::SharedData.DefaultValueIntKeyClassWithExplicitConstructor Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -2056,10 +2032,10 @@ namespace MessagePack.Formatters.SharedData
                         __Prop2__ = reader.ReadInt32();
                         break;
                     case 2:
-                        __Prop3__ = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                        __Prop3__ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 3:
-                        __Prop4__ = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                        __Prop4__ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     default:
                         reader.Skip();
@@ -2200,15 +2176,15 @@ namespace MessagePack.Formatters.SharedData
         {
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(9);
-            formatterResolver.GetFormatterWithVerify<T1>().Serialize(ref writer, value.Item1, options);
-            formatterResolver.GetFormatterWithVerify<T2>().Serialize(ref writer, value.Item2, options);
-            formatterResolver.GetFormatterWithVerify<T3>().Serialize(ref writer, value.Item3, options);
-            formatterResolver.GetFormatterWithVerify<T4>().Serialize(ref writer, value.Item4, options);
-            formatterResolver.GetFormatterWithVerify<T5>().Serialize(ref writer, value.Item5, options);
-            formatterResolver.GetFormatterWithVerify<T6>().Serialize(ref writer, value.Item6, options);
-            formatterResolver.GetFormatterWithVerify<T7>().Serialize(ref writer, value.Item7, options);
-            formatterResolver.GetFormatterWithVerify<T8>().Serialize(ref writer, value.Item8, options);
-            formatterResolver.GetFormatterWithVerify<T9>().Serialize(ref writer, value.Item9, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Serialize(ref writer, value.Item1, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Serialize(ref writer, value.Item2, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T3>(formatterResolver).Serialize(ref writer, value.Item3, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T4>(formatterResolver).Serialize(ref writer, value.Item4, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T5>(formatterResolver).Serialize(ref writer, value.Item5, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T6>(formatterResolver).Serialize(ref writer, value.Item6, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T7>(formatterResolver).Serialize(ref writer, value.Item7, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T8>(formatterResolver).Serialize(ref writer, value.Item8, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T9>(formatterResolver).Serialize(ref writer, value.Item9, options);
         }
 
         public global::SharedData.DynamicArgumentTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9> Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -2236,31 +2212,31 @@ namespace MessagePack.Formatters.SharedData
                 switch (i)
                 {
                     case 0:
-                        __Item1__ = formatterResolver.GetFormatterWithVerify<T1>().Deserialize(ref reader, options);
+                        __Item1__ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 1:
-                        __Item2__ = formatterResolver.GetFormatterWithVerify<T2>().Deserialize(ref reader, options);
+                        __Item2__ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 2:
-                        __Item3__ = formatterResolver.GetFormatterWithVerify<T3>().Deserialize(ref reader, options);
+                        __Item3__ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T3>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 3:
-                        __Item4__ = formatterResolver.GetFormatterWithVerify<T4>().Deserialize(ref reader, options);
+                        __Item4__ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T4>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 4:
-                        __Item5__ = formatterResolver.GetFormatterWithVerify<T5>().Deserialize(ref reader, options);
+                        __Item5__ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T5>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 5:
-                        __Item6__ = formatterResolver.GetFormatterWithVerify<T6>().Deserialize(ref reader, options);
+                        __Item6__ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T6>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 6:
-                        __Item7__ = formatterResolver.GetFormatterWithVerify<T7>().Deserialize(ref reader, options);
+                        __Item7__ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T7>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 7:
-                        __Item8__ = formatterResolver.GetFormatterWithVerify<T8>().Deserialize(ref reader, options);
+                        __Item8__ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T8>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 8:
-                        __Item9__ = formatterResolver.GetFormatterWithVerify<T9>().Deserialize(ref reader, options);
+                        __Item9__ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T9>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     default:
                         reader.Skip();
@@ -2360,7 +2336,7 @@ namespace MessagePack.Formatters.SharedData
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(3);
             writer.Write(value.Prop1);
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.Prop2, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.Prop2, options);
             writer.Write(value.Prop3);
         }
 
@@ -2384,7 +2360,7 @@ namespace MessagePack.Formatters.SharedData
                         ____result.Prop1 = reader.ReadInt32();
                         break;
                     case 1:
-                        ____result.Prop2 = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                        ____result.Prop2 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 2:
                         ____result.Prop3 = reader.ReadInt32();
@@ -2457,8 +2433,8 @@ namespace MessagePack.Formatters.SharedData
 
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(2);
-            formatterResolver.GetFormatterWithVerify<T1>().Serialize(ref writer, value.MyProperty0, options);
-            formatterResolver.GetFormatterWithVerify<T2>().Serialize(ref writer, value.MyProperty1, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Serialize(ref writer, value.MyProperty0, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Serialize(ref writer, value.MyProperty1, options);
         }
 
         public global::SharedData.GenericClass<T1, T2> Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -2478,10 +2454,10 @@ namespace MessagePack.Formatters.SharedData
                 switch (i)
                 {
                     case 0:
-                        ____result.MyProperty0 = formatterResolver.GetFormatterWithVerify<T1>().Deserialize(ref reader, options);
+                        ____result.MyProperty0 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 1:
-                        ____result.MyProperty1 = formatterResolver.GetFormatterWithVerify<T2>().Deserialize(ref reader, options);
+                        ____result.MyProperty1 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     default:
                         reader.Skip();
@@ -2509,8 +2485,8 @@ namespace MessagePack.Formatters.SharedData
 
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(2);
-            formatterResolver.GetFormatterWithVerify<T1>().Serialize(ref writer, value.MyProperty0, options);
-            formatterResolver.GetFormatterWithVerify<T2>().Serialize(ref writer, value.Comparer, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Serialize(ref writer, value.MyProperty0, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Serialize(ref writer, value.Comparer, options);
         }
 
         public global::SharedData.GenericConstrainedClassIntKey<T1, T2> Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -2530,10 +2506,10 @@ namespace MessagePack.Formatters.SharedData
                 switch (i)
                 {
                     case 0:
-                        ____result.MyProperty0 = formatterResolver.GetFormatterWithVerify<T1>().Deserialize(ref reader, options);
+                        ____result.MyProperty0 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 1:
-                        ____result.Comparer = formatterResolver.GetFormatterWithVerify<T2>().Deserialize(ref reader, options);
+                        ____result.Comparer = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     default:
                         reader.Skip();
@@ -2555,8 +2531,8 @@ namespace MessagePack.Formatters.SharedData
         {
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(2);
-            formatterResolver.GetFormatterWithVerify<T1>().Serialize(ref writer, value.MyProperty0, options);
-            formatterResolver.GetFormatterWithVerify<T2>().Serialize(ref writer, value.Comparer, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Serialize(ref writer, value.MyProperty0, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Serialize(ref writer, value.Comparer, options);
         }
 
         public global::SharedData.GenericConstrainedStructIntKey<T1, T2> Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -2576,10 +2552,10 @@ namespace MessagePack.Formatters.SharedData
                 switch (i)
                 {
                     case 0:
-                        ____result.MyProperty0 = formatterResolver.GetFormatterWithVerify<T1>().Deserialize(ref reader, options);
+                        ____result.MyProperty0 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 1:
-                        ____result.Comparer = formatterResolver.GetFormatterWithVerify<T2>().Deserialize(ref reader, options);
+                        ____result.Comparer = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     default:
                         reader.Skip();
@@ -2599,8 +2575,8 @@ namespace MessagePack.Formatters.SharedData
         {
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(2);
-            formatterResolver.GetFormatterWithVerify<T1>().Serialize(ref writer, value.MyProperty0, options);
-            formatterResolver.GetFormatterWithVerify<T2>().Serialize(ref writer, value.MyProperty1, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Serialize(ref writer, value.MyProperty0, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Serialize(ref writer, value.MyProperty1, options);
         }
 
         public global::SharedData.GenericStruct<T1, T2> Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -2620,10 +2596,10 @@ namespace MessagePack.Formatters.SharedData
                 switch (i)
                 {
                     case 0:
-                        ____result.MyProperty0 = formatterResolver.GetFormatterWithVerify<T1>().Deserialize(ref reader, options);
+                        ____result.MyProperty0 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 1:
-                        ____result.MyProperty1 = formatterResolver.GetFormatterWithVerify<T2>().Deserialize(ref reader, options);
+                        ____result.MyProperty1 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     default:
                         reader.Skip();
@@ -2649,7 +2625,7 @@ namespace MessagePack.Formatters.SharedData
 
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(2);
-            formatterResolver.GetFormatterWithVerify<global::SharedData.Version0>().Serialize(ref writer, value.MyProperty1, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.Version0>(formatterResolver).Serialize(ref writer, value.MyProperty1, options);
             writer.Write(value.After);
         }
 
@@ -2670,7 +2646,7 @@ namespace MessagePack.Formatters.SharedData
                 switch (i)
                 {
                     case 0:
-                        ____result.MyProperty1 = formatterResolver.GetFormatterWithVerify<global::SharedData.Version0>().Deserialize(ref reader, options);
+                        ____result.MyProperty1 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.Version0>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 1:
                         ____result.After = reader.ReadInt32();
@@ -2699,7 +2675,7 @@ namespace MessagePack.Formatters.SharedData
 
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(2);
-            formatterResolver.GetFormatterWithVerify<global::SharedData.Version1>().Serialize(ref writer, value.MyProperty1, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.Version1>(formatterResolver).Serialize(ref writer, value.MyProperty1, options);
             writer.Write(value.After);
         }
 
@@ -2720,7 +2696,7 @@ namespace MessagePack.Formatters.SharedData
                 switch (i)
                 {
                     case 0:
-                        ____result.MyProperty1 = formatterResolver.GetFormatterWithVerify<global::SharedData.Version1>().Deserialize(ref reader, options);
+                        ____result.MyProperty1 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.Version1>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 1:
                         ____result.After = reader.ReadInt32();
@@ -2749,7 +2725,7 @@ namespace MessagePack.Formatters.SharedData
 
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(2);
-            formatterResolver.GetFormatterWithVerify<global::SharedData.Version2>().Serialize(ref writer, value.MyProperty1, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.Version2>(formatterResolver).Serialize(ref writer, value.MyProperty1, options);
             writer.Write(value.After);
         }
 
@@ -2770,7 +2746,7 @@ namespace MessagePack.Formatters.SharedData
                 switch (i)
                 {
                     case 0:
-                        ____result.MyProperty1 = formatterResolver.GetFormatterWithVerify<global::SharedData.Version2>().Deserialize(ref reader, options);
+                        ____result.MyProperty1 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.Version2>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 1:
                         ____result.After = reader.ReadInt32();
@@ -3121,11 +3097,11 @@ namespace MessagePack.Formatters.SharedData
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(7);
             writer.Write(value.Prop1);
-            formatterResolver.GetFormatterWithVerify<global::SharedData.ByteEnum>().Serialize(ref writer, value.Prop2, options);
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.Prop3, options);
-            formatterResolver.GetFormatterWithVerify<global::SharedData.SimpleStringKeyData>().Serialize(ref writer, value.Prop4, options);
-            formatterResolver.GetFormatterWithVerify<global::SharedData.SimpleStructIntKeyData>().Serialize(ref writer, value.Prop5, options);
-            formatterResolver.GetFormatterWithVerify<global::SharedData.SimpleStructStringKeyData>().Serialize(ref writer, value.Prop6, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.ByteEnum>(formatterResolver).Serialize(ref writer, value.Prop2, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.Prop3, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.SimpleStringKeyData>(formatterResolver).Serialize(ref writer, value.Prop4, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.SimpleStructIntKeyData>(formatterResolver).Serialize(ref writer, value.Prop5, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.SimpleStructStringKeyData>(formatterResolver).Serialize(ref writer, value.Prop6, options);
             writer.Write(value.BytesSpecial);
         }
 
@@ -3149,22 +3125,22 @@ namespace MessagePack.Formatters.SharedData
                         ____result.Prop1 = reader.ReadInt32();
                         break;
                     case 1:
-                        ____result.Prop2 = formatterResolver.GetFormatterWithVerify<global::SharedData.ByteEnum>().Deserialize(ref reader, options);
+                        ____result.Prop2 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.ByteEnum>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 2:
-                        ____result.Prop3 = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                        ____result.Prop3 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 3:
-                        ____result.Prop4 = formatterResolver.GetFormatterWithVerify<global::SharedData.SimpleStringKeyData>().Deserialize(ref reader, options);
+                        ____result.Prop4 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.SimpleStringKeyData>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 4:
-                        ____result.Prop5 = formatterResolver.GetFormatterWithVerify<global::SharedData.SimpleStructIntKeyData>().Deserialize(ref reader, options);
+                        ____result.Prop5 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.SimpleStructIntKeyData>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 5:
-                        ____result.Prop6 = formatterResolver.GetFormatterWithVerify<global::SharedData.SimpleStructStringKeyData>().Deserialize(ref reader, options);
+                        ____result.Prop6 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.SimpleStructStringKeyData>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 6:
-                        ____result.BytesSpecial = reader.ReadBytes()?.ToArray();
+                        ____result.BytesSpecial = global::MessagePack.Internal.CodeGenHelpers.GetArrayFromNullableSequence(reader.ReadBytes());
                         break;
                     default:
                         reader.Skip();
@@ -3210,7 +3186,7 @@ namespace MessagePack.Formatters.SharedData
                         ____result.Y = reader.ReadInt32();
                         break;
                     case 2:
-                        ____result.BytesSpecial = reader.ReadBytes()?.ToArray();
+                        ____result.BytesSpecial = global::MessagePack.Internal.CodeGenHelpers.GetArrayFromNullableSequence(reader.ReadBytes());
                         break;
                     default:
                         reader.Skip();
@@ -3681,7 +3657,7 @@ namespace MessagePack.Formatters.SharedData
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(3);
             writer.Write(value.MyProperty);
-            formatterResolver.GetFormatterWithVerify<global::SharedData.MyClass>().Serialize(ref writer, value.UnknownBlock, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.MyClass>(formatterResolver).Serialize(ref writer, value.UnknownBlock, options);
             writer.Write(value.MyProperty2);
         }
 
@@ -3705,7 +3681,7 @@ namespace MessagePack.Formatters.SharedData
                         ____result.MyProperty = reader.ReadInt32();
                         break;
                     case 1:
-                        ____result.UnknownBlock = formatterResolver.GetFormatterWithVerify<global::SharedData.MyClass>().Deserialize(ref reader, options);
+                        ____result.UnknownBlock = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.MyClass>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     case 2:
                         ____result.MyProperty2 = reader.ReadInt32();
@@ -3786,7 +3762,7 @@ namespace MessagePack.Formatters.SharedData
             global::MessagePack.IFormatterResolver formatterResolver = options.Resolver;
             writer.WriteArrayHeader(2);
             writer.Write(value.Data1);
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.Data2, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.Data2, options);
         }
 
         public global::SharedData.WithIndexer Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -3809,7 +3785,7 @@ namespace MessagePack.Formatters.SharedData
                         ____result.Data1 = reader.ReadInt32();
                         break;
                     case 1:
-                        ____result.Data2 = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                        ____result.Data2 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                         break;
                     default:
                         reader.Skip();
@@ -3821,6 +3797,7 @@ namespace MessagePack.Formatters.SharedData
             return ____result;
         }
     }
+
 }
 
 #pragma warning restore 168
@@ -3829,7 +3806,6 @@ namespace MessagePack.Formatters.SharedData
 #pragma warning restore 612
 
 #pragma warning restore SA1129 // Do not use default value type constructor
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1309 // Field names should not begin with underscore
 #pragma warning restore SA1312 // Variable names should begin with lower-case letter
 #pragma warning restore SA1403 // File may only contain a single namespace
@@ -3845,7 +3821,6 @@ namespace MessagePack.Formatters.SharedData
 #pragma warning disable 168
 
 #pragma warning disable SA1129 // Do not use default value type constructor
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1309 // Field names should not begin with underscore
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1403 // File may only contain a single namespace
@@ -3853,9 +3828,6 @@ namespace MessagePack.Formatters.SharedData
 
 namespace MessagePack.Formatters.SharedData
 {
-    using global::System.Buffers;
-    using global::MessagePack;
-
     public sealed class Callback2Formatter : global::MessagePack.Formatters.IMessagePackFormatter<global::SharedData.Callback2>
     {
         // X
@@ -4198,9 +4170,9 @@ namespace MessagePack.Formatters.SharedData
             var formatterResolver = options.Resolver;
             writer.WriteMapHeader(2);
             writer.WriteRaw(GetSpan_MyProperty0());
-            formatterResolver.GetFormatterWithVerify<T1>().Serialize(ref writer, value.MyProperty0, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Serialize(ref writer, value.MyProperty0, options);
             writer.WriteRaw(GetSpan_Comparer());
-            formatterResolver.GetFormatterWithVerify<T2>().Serialize(ref writer, value.Comparer, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Serialize(ref writer, value.Comparer, options);
         }
 
         public global::SharedData.GenericConstrainedClassStringKey<T1, T2> Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -4227,12 +4199,12 @@ namespace MessagePack.Formatters.SharedData
                     case 11:
                         if (!global::System.MemoryExtensions.SequenceEqual(stringKey, GetSpan_MyProperty0().Slice(1))) { goto FAIL; }
 
-                        ____result.MyProperty0 = formatterResolver.GetFormatterWithVerify<T1>().Deserialize(ref reader, options);
+                        ____result.MyProperty0 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Deserialize(ref reader, options);
                         continue;
                     case 8:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 8243120455795175235UL) { goto FAIL; }
 
-                        ____result.Comparer = formatterResolver.GetFormatterWithVerify<T2>().Deserialize(ref reader, options);
+                        ____result.Comparer = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Deserialize(ref reader, options);
                         continue;
 
                 }
@@ -4257,9 +4229,9 @@ namespace MessagePack.Formatters.SharedData
             var formatterResolver = options.Resolver;
             writer.WriteMapHeader(2);
             writer.WriteRaw(GetSpan_MyProperty0());
-            formatterResolver.GetFormatterWithVerify<T1>().Serialize(ref writer, value.MyProperty0, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Serialize(ref writer, value.MyProperty0, options);
             writer.WriteRaw(GetSpan_Comparer());
-            formatterResolver.GetFormatterWithVerify<T2>().Serialize(ref writer, value.Comparer, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Serialize(ref writer, value.Comparer, options);
         }
 
         public global::SharedData.GenericConstrainedStructStringKey<T1, T2> Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -4286,12 +4258,12 @@ namespace MessagePack.Formatters.SharedData
                     case 11:
                         if (!global::System.MemoryExtensions.SequenceEqual(stringKey, GetSpan_MyProperty0().Slice(1))) { goto FAIL; }
 
-                        ____result.MyProperty0 = formatterResolver.GetFormatterWithVerify<T1>().Deserialize(ref reader, options);
+                        ____result.MyProperty0 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T1>(formatterResolver).Deserialize(ref reader, options);
                         continue;
                     case 8:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 8243120455795175235UL) { goto FAIL; }
 
-                        ____result.Comparer = formatterResolver.GetFormatterWithVerify<T2>().Deserialize(ref reader, options);
+                        ____result.Comparer = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<T2>(formatterResolver).Deserialize(ref reader, options);
                         continue;
 
                 }
@@ -4376,7 +4348,7 @@ namespace MessagePack.Formatters.SharedData
             writer.WriteRaw(GetSpan_Prop1());
             writer.Write(value.Prop1);
             writer.WriteRaw(GetSpan_Prop2());
-            formatterResolver.GetFormatterWithVerify<global::SharedData.ByteEnum>().Serialize(ref writer, value.Prop2, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.ByteEnum>(formatterResolver).Serialize(ref writer, value.Prop2, options);
             writer.WriteRaw(GetSpan_Prop3());
             writer.Write(value.Prop3);
         }
@@ -4410,7 +4382,7 @@ namespace MessagePack.Formatters.SharedData
                                 ____result.Prop1 = reader.ReadInt32();
                                 continue;
                             case 216634716752UL:
-                                ____result.Prop2 = formatterResolver.GetFormatterWithVerify<global::SharedData.ByteEnum>().Deserialize(ref reader, options);
+                                ____result.Prop2 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::SharedData.ByteEnum>(formatterResolver).Deserialize(ref reader, options);
                                 continue;
                             case 220929684048UL:
                                 ____result.Prop3 = reader.ReadInt32();
@@ -4439,7 +4411,7 @@ namespace MessagePack.Formatters.SharedData
             writer.WriteRaw(GetSpan_X());
             writer.Write(value.X);
             writer.WriteRaw(GetSpan_Y());
-            formatterResolver.GetFormatterWithVerify<int[]>().Serialize(ref writer, value.Y, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<int[]>(formatterResolver).Serialize(ref writer, value.Y, options);
         }
 
         public global::SharedData.SimpleStructStringKeyData Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -4471,7 +4443,7 @@ namespace MessagePack.Formatters.SharedData
                                 ____result.X = reader.ReadInt32();
                                 continue;
                             case 383015019883UL:
-                                ____result.Y = formatterResolver.GetFormatterWithVerify<int[]>().Deserialize(ref reader, options);
+                                ____result.Y = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<int[]>(formatterResolver).Deserialize(ref reader, options);
                                 continue;
                         }
 
@@ -4482,5 +4454,17 @@ namespace MessagePack.Formatters.SharedData
             return ____result;
         }
     }
+
 }
 
+#pragma warning restore 168
+#pragma warning restore 414
+#pragma warning restore 618
+#pragma warning restore 612
+
+#pragma warning restore SA1129 // Do not use default value type constructor
+#pragma warning restore SA1309 // Field names should not begin with underscore
+#pragma warning restore SA1312 // Variable names should begin with lower-case letter
+#pragma warning restore SA1403 // File may only contain a single namespace
+#pragma warning restore SA1649 // File name should match first type name
+
diff --git a/sandbox/TestData2/Generated.cs b/sandbox/TestData2/Generated.cs
index 606e2dca..e4f08ad5 100644
--- a/sandbox/TestData2/Generated.cs
+++ b/sandbox/TestData2/Generated.cs
@@ -7,14 +7,11 @@
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace MessagePack.Resolvers
 {
-    using System;
-
     public class GeneratedResolver : global::MessagePack.IFormatterResolver
     {
         public static readonly global::MessagePack.IFormatterResolver Instance = new GeneratedResolver();
@@ -45,11 +42,11 @@ namespace MessagePack.Resolvers
 
     internal static class GeneratedResolverGetFormatterHelper
     {
-        private static readonly global::System.Collections.Generic.Dictionary<Type, int> lookup;
+        private static readonly global::System.Collections.Generic.Dictionary<global::System.Type, int> lookup;
 
         static GeneratedResolverGetFormatterHelper()
         {
-            lookup = new global::System.Collections.Generic.Dictionary<Type, int>(14)
+            lookup = new global::System.Collections.Generic.Dictionary<global::System.Type, int>(14)
             {
                 { typeof(global::System.Collections.Generic.List<global::TestData2.A>), 0 },
                 { typeof(global::System.Collections.Generic.List<global::TestData2.B>), 1 },
@@ -68,7 +65,7 @@ namespace MessagePack.Resolvers
             };
         }
 
-        internal static object GetFormatter(Type t)
+        internal static object GetFormatter(global::System.Type t)
         {
             int key;
             if (!lookup.TryGetValue(t, out key))
@@ -104,7 +101,6 @@ namespace MessagePack.Resolvers
 #pragma warning restore 612
 
 #pragma warning restore SA1312 // Variable names should begin with lower-case letter
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1649 // File name should match first type name
 
 
@@ -117,24 +113,20 @@ namespace MessagePack.Resolvers
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1403 // File may only contain a single namespace
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace MessagePack.Formatters.TestData2
 {
-    using System;
-    using System.Buffers;
-    using MessagePack;
 
     public sealed class Nest1_IdFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::TestData2.Nest1.Id>
     {
-        public void Serialize(ref MessagePackWriter writer, global::TestData2.Nest1.Id value, global::MessagePack.MessagePackSerializerOptions options)
+        public void Serialize(ref global::MessagePack.MessagePackWriter writer, global::TestData2.Nest1.Id value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            writer.Write((Int32)value);
+            writer.Write((global::System.Int32)value);
         }
 
-        public global::TestData2.Nest1.Id Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+        public global::TestData2.Nest1.Id Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             return (global::TestData2.Nest1.Id)reader.ReadInt32();
         }
@@ -142,12 +134,12 @@ namespace MessagePack.Formatters.TestData2
 
     public sealed class Nest2_IdFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::TestData2.Nest2.Id>
     {
-        public void Serialize(ref MessagePackWriter writer, global::TestData2.Nest2.Id value, global::MessagePack.MessagePackSerializerOptions options)
+        public void Serialize(ref global::MessagePack.MessagePackWriter writer, global::TestData2.Nest2.Id value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            writer.Write((Int32)value);
+            writer.Write((global::System.Int32)value);
         }
 
-        public global::TestData2.Nest2.Id Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+        public global::TestData2.Nest2.Id Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             return (global::TestData2.Nest2.Id)reader.ReadInt32();
         }
@@ -159,7 +151,6 @@ namespace MessagePack.Formatters.TestData2
 #pragma warning restore 618
 #pragma warning restore 612
 
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1403 // File may only contain a single namespace
 #pragma warning restore SA1649 // File name should match first type name
 
@@ -175,7 +166,6 @@ namespace MessagePack.Formatters.TestData2
 #pragma warning disable 168
 
 #pragma warning disable SA1129 // Do not use default value type constructor
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1309 // Field names should not begin with underscore
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1403 // File may only contain a single namespace
@@ -183,9 +173,6 @@ namespace MessagePack.Formatters.TestData2
 
 namespace MessagePack.Formatters.TestData2
 {
-    using global::System.Buffers;
-    using global::MessagePack;
-
     public sealed class AFormatter : global::MessagePack.Formatters.IMessagePackFormatter<global::TestData2.A>
     {
         // a
@@ -208,9 +195,9 @@ namespace MessagePack.Formatters.TestData2
             writer.WriteRaw(GetSpan_a());
             writer.Write(value.a);
             writer.WriteRaw(GetSpan_bs());
-            formatterResolver.GetFormatterWithVerify<global::System.Collections.Generic.List<global::TestData2.B>>().Serialize(ref writer, value.bs, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.Collections.Generic.List<global::TestData2.B>>(formatterResolver).Serialize(ref writer, value.bs, options);
             writer.WriteRaw(GetSpan_c());
-            formatterResolver.GetFormatterWithVerify<global::TestData2.C>().Serialize(ref writer, value.c, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.C>(formatterResolver).Serialize(ref writer, value.c, options);
         }
 
         public global::TestData2.A Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -242,13 +229,13 @@ namespace MessagePack.Formatters.TestData2
                                 ____result.a = reader.ReadInt32();
                                 continue;
                             case 99UL:
-                                ____result.c = formatterResolver.GetFormatterWithVerify<global::TestData2.C>().Deserialize(ref reader, options);
+                                ____result.c = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.C>(formatterResolver).Deserialize(ref reader, options);
                                 continue;
                         }
                     case 2:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 29538UL) { goto FAIL; }
 
-                        ____result.bs = formatterResolver.GetFormatterWithVerify<global::System.Collections.Generic.List<global::TestData2.B>>().Deserialize(ref reader, options);
+                        ____result.bs = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.Collections.Generic.List<global::TestData2.B>>(formatterResolver).Deserialize(ref reader, options);
                         continue;
 
                 }
@@ -279,9 +266,9 @@ namespace MessagePack.Formatters.TestData2
             var formatterResolver = options.Resolver;
             writer.WriteMapHeader(3);
             writer.WriteRaw(GetSpan_ass());
-            formatterResolver.GetFormatterWithVerify<global::System.Collections.Generic.List<global::TestData2.A>>().Serialize(ref writer, value.ass, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.Collections.Generic.List<global::TestData2.A>>(formatterResolver).Serialize(ref writer, value.ass, options);
             writer.WriteRaw(GetSpan_c());
-            formatterResolver.GetFormatterWithVerify<global::TestData2.C>().Serialize(ref writer, value.c, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.C>(formatterResolver).Serialize(ref writer, value.c, options);
             writer.WriteRaw(GetSpan_a());
             writer.Write(value.a);
         }
@@ -310,14 +297,14 @@ namespace MessagePack.Formatters.TestData2
                     case 3:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 7566177UL) { goto FAIL; }
 
-                        ____result.ass = formatterResolver.GetFormatterWithVerify<global::System.Collections.Generic.List<global::TestData2.A>>().Deserialize(ref reader, options);
+                        ____result.ass = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::System.Collections.Generic.List<global::TestData2.A>>(formatterResolver).Deserialize(ref reader, options);
                         continue;
                     case 1:
                         switch (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey))
                         {
                             default: goto FAIL;
                             case 99UL:
-                                ____result.c = formatterResolver.GetFormatterWithVerify<global::TestData2.C>().Deserialize(ref reader, options);
+                                ____result.c = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.C>(formatterResolver).Deserialize(ref reader, options);
                                 continue;
                             case 97UL:
                                 ____result.a = reader.ReadInt32();
@@ -350,7 +337,7 @@ namespace MessagePack.Formatters.TestData2
             var formatterResolver = options.Resolver;
             writer.WriteMapHeader(2);
             writer.WriteRaw(GetSpan_b());
-            formatterResolver.GetFormatterWithVerify<global::TestData2.B>().Serialize(ref writer, value.b, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.B>(formatterResolver).Serialize(ref writer, value.b, options);
             writer.WriteRaw(GetSpan_a());
             writer.Write(value.a);
         }
@@ -381,7 +368,7 @@ namespace MessagePack.Formatters.TestData2
                         {
                             default: goto FAIL;
                             case 98UL:
-                                ____result.b = formatterResolver.GetFormatterWithVerify<global::TestData2.B>().Deserialize(ref reader, options);
+                                ____result.b = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.B>(formatterResolver).Deserialize(ref reader, options);
                                 continue;
                             case 97UL:
                                 ____result.a = reader.ReadInt32();
@@ -414,9 +401,9 @@ namespace MessagePack.Formatters.TestData2
             var formatterResolver = options.Resolver;
             writer.WriteMapHeader(2);
             writer.WriteRaw(GetSpan_EnumId());
-            formatterResolver.GetFormatterWithVerify<global::TestData2.Nest1.Id>().Serialize(ref writer, value.EnumId, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.Nest1.Id>(formatterResolver).Serialize(ref writer, value.EnumId, options);
             writer.WriteRaw(GetSpan_ClassId());
-            formatterResolver.GetFormatterWithVerify<global::TestData2.Nest1.IdType>().Serialize(ref writer, value.ClassId, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.Nest1.IdType>(formatterResolver).Serialize(ref writer, value.ClassId, options);
         }
 
         public global::TestData2.Nest1 Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -443,12 +430,12 @@ namespace MessagePack.Formatters.TestData2
                     case 6:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 110266531802693UL) { goto FAIL; }
 
-                        ____result.EnumId = formatterResolver.GetFormatterWithVerify<global::TestData2.Nest1.Id>().Deserialize(ref reader, options);
+                        ____result.EnumId = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.Nest1.Id>(formatterResolver).Deserialize(ref reader, options);
                         continue;
                     case 7:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 28228257876896835UL) { goto FAIL; }
 
-                        ____result.ClassId = formatterResolver.GetFormatterWithVerify<global::TestData2.Nest1.IdType>().Deserialize(ref reader, options);
+                        ____result.ClassId = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.Nest1.IdType>(formatterResolver).Deserialize(ref reader, options);
                         continue;
 
                 }
@@ -503,9 +490,9 @@ namespace MessagePack.Formatters.TestData2
             var formatterResolver = options.Resolver;
             writer.WriteMapHeader(2);
             writer.WriteRaw(GetSpan_EnumId());
-            formatterResolver.GetFormatterWithVerify<global::TestData2.Nest2.Id>().Serialize(ref writer, value.EnumId, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.Nest2.Id>(formatterResolver).Serialize(ref writer, value.EnumId, options);
             writer.WriteRaw(GetSpan_ClassId());
-            formatterResolver.GetFormatterWithVerify<global::TestData2.Nest2.IdType>().Serialize(ref writer, value.ClassId, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.Nest2.IdType>(formatterResolver).Serialize(ref writer, value.ClassId, options);
         }
 
         public global::TestData2.Nest2 Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -532,12 +519,12 @@ namespace MessagePack.Formatters.TestData2
                     case 6:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 110266531802693UL) { goto FAIL; }
 
-                        ____result.EnumId = formatterResolver.GetFormatterWithVerify<global::TestData2.Nest2.Id>().Deserialize(ref reader, options);
+                        ____result.EnumId = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.Nest2.Id>(formatterResolver).Deserialize(ref reader, options);
                         continue;
                     case 7:
                         if (global::MessagePack.Internal.AutomataKeyGen.GetKey(ref stringKey) != 28228257876896835UL) { goto FAIL; }
 
-                        ____result.ClassId = formatterResolver.GetFormatterWithVerify<global::TestData2.Nest2.IdType>().Deserialize(ref reader, options);
+                        ____result.ClassId = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<global::TestData2.Nest2.IdType>(formatterResolver).Deserialize(ref reader, options);
                         continue;
 
                 }
@@ -592,9 +579,9 @@ namespace MessagePack.Formatters.TestData2
             var formatterResolver = options.Resolver;
             writer.WriteMapHeader(2);
             writer.WriteRaw(GetSpan_MyProperty1());
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.MyProperty1, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.MyProperty1, options);
             writer.WriteRaw(GetSpan_MyProperty2());
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.MyProperty2, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.MyProperty2, options);
         }
 
         public global::TestData2.PropNameCheck1 Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -627,10 +614,10 @@ namespace MessagePack.Formatters.TestData2
                                 {
                                     default: goto FAIL;
                                     case 3242356UL:
-                                        ____result.MyProperty1 = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                                        ____result.MyProperty1 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                                         continue;
                                     case 3307892UL:
-                                        ____result.MyProperty2 = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                                        ____result.MyProperty2 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                                         continue;
                                 }
 
@@ -662,9 +649,9 @@ namespace MessagePack.Formatters.TestData2
             var formatterResolver = options.Resolver;
             writer.WriteMapHeader(2);
             writer.WriteRaw(GetSpan_MyProperty1());
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.MyProperty1, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.MyProperty1, options);
             writer.WriteRaw(GetSpan_MyProperty2());
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.MyProperty2, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.MyProperty2, options);
         }
 
         public global::TestData2.PropNameCheck2 Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -697,10 +684,10 @@ namespace MessagePack.Formatters.TestData2
                                 {
                                     default: goto FAIL;
                                     case 3242356UL:
-                                        ____result.MyProperty1 = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                                        ____result.MyProperty1 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                                         continue;
                                     case 3307892UL:
-                                        ____result.MyProperty2 = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                                        ____result.MyProperty2 = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                                         continue;
                                 }
 
@@ -730,7 +717,7 @@ namespace MessagePack.Formatters.TestData2
             var formatterResolver = options.Resolver;
             writer.WriteMapHeader(1);
             writer.WriteRaw(GetSpan_SomeProperty());
-            formatterResolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.SomeProperty, options);
+            global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Serialize(ref writer, value.SomeProperty, options);
         }
 
         public global::TestData2.Record Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
@@ -757,7 +744,7 @@ namespace MessagePack.Formatters.TestData2
                     case 12:
                         if (!global::System.MemoryExtensions.SequenceEqual(stringKey, GetSpan_SomeProperty().Slice(1))) { goto FAIL; }
 
-                        __SomeProperty__ = formatterResolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
+                        __SomeProperty__ = global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<string>(formatterResolver).Deserialize(ref reader, options);
                         continue;
 
                 }
@@ -768,5 +755,17 @@ namespace MessagePack.Formatters.TestData2
             return ____result;
         }
     }
+
 }
 
+#pragma warning restore 168
+#pragma warning restore 414
+#pragma warning restore 618
+#pragma warning restore 612
+
+#pragma warning restore SA1129 // Do not use default value type constructor
+#pragma warning restore SA1309 // Field names should not begin with underscore
+#pragma warning restore SA1312 // Variable names should begin with lower-case letter
+#pragma warning restore SA1403 // File may only contain a single namespace
+#pragma warning restore SA1649 // File name should match first type name
+
diff --git a/src/MessagePack.GeneratorCore/CodeAnalysis/Definitions.cs b/src/MessagePack.GeneratorCore/CodeAnalysis/Definitions.cs
index 532cdc71..30aaedb9 100644
--- a/src/MessagePack.GeneratorCore/CodeAnalysis/Definitions.cs
+++ b/src/MessagePack.GeneratorCore/CodeAnalysis/Definitions.cs
@@ -170,7 +170,7 @@ namespace MessagePackCompiler.CodeAnalysis
             }
             else
             {
-                return $"formatterResolver.GetFormatterWithVerify<{this.Type}>().Serialize(ref writer, value.{this.Name}, options)";
+                return $"global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<{this.Type}>(formatterResolver).Serialize(ref writer, value.{this.Name}, options)";
             }
         }
 
@@ -182,12 +182,18 @@ namespace MessagePackCompiler.CodeAnalysis
             }
             else if (this.primitiveTypes.Contains(this.Type))
             {
-                string suffix = this.Type == "byte[]" ? "?.ToArray()" : string.Empty;
-                return $"reader.Read{this.ShortTypeName!.Replace("[]", "s")}()" + suffix;
+                if (this.Type == "byte[]")
+                {
+                    return "global::MessagePack.Internal.CodeGenHelpers.GetArrayFromNullableSequence(reader.ReadBytes())";
+                }
+                else
+                {
+                    return $"reader.Read{this.ShortTypeName!.Replace("[]", "s")}()";
+                }
             }
             else
             {
-                return $"formatterResolver.GetFormatterWithVerify<{this.Type}>().Deserialize(ref reader, options)";
+                return $"global::MessagePack.FormatterResolverExtensions.GetFormatterWithVerify<{this.Type}>(formatterResolver).Deserialize(ref reader, options)";
             }
         }
     }
diff --git a/src/MessagePack.GeneratorCore/Generator/EnumTemplate.cs b/src/MessagePack.GeneratorCore/Generator/EnumTemplate.cs
index 814a3123..66c9fc14 100644
--- a/src/MessagePack.GeneratorCore/Generator/EnumTemplate.cs
+++ b/src/MessagePack.GeneratorCore/Generator/EnumTemplate.cs
@@ -34,27 +34,27 @@ namespace MessagePackCompiler.Generator
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1403 // File may only contain a single namespace
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace ");
             this.Write(this.ToStringHelper.ToStringWithCulture(Namespace));
-            this.Write("\r\n{\r\n    using System;\r\n    using System.Buffers;\r\n    using MessagePack;\r\n");
+            this.Write("\r\n{\r\n");
  foreach(var info in EnumSerializationInfos) { 
             this.Write("\r\n    public sealed class ");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.Name));
             this.Write("Formatter : global::MessagePack.Formatters.IMessagePackFormatter<");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.FullName));
-            this.Write(">\r\n    {\r\n        public void Serialize(ref MessagePackWriter writer, ");
+            this.Write(">\r\n    {\r\n        public void Serialize(ref global::MessagePack.MessagePackWriter" +
+                    " writer, ");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.FullName));
             this.Write(" value, global::MessagePack.MessagePackSerializerOptions options)\r\n        {\r\n   " +
-                    "         writer.Write((");
+                    "         writer.Write((global::System.");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.UnderlyingType));
             this.Write(")value);\r\n        }\r\n\r\n        public ");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.FullName));
-            this.Write(" Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSeriali" +
-                    "zerOptions options)\r\n        {\r\n            return (");
+            this.Write(" Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePac" +
+                    "k.MessagePackSerializerOptions options)\r\n        {\r\n            return (");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.FullName));
             this.Write(")reader.Read");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.UnderlyingType));
@@ -67,7 +67,6 @@ namespace ");
 #pragma warning restore 618
 #pragma warning restore 612
 
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1403 // File may only contain a single namespace
 #pragma warning restore SA1649 // File name should match first type name
 ");
diff --git a/src/MessagePack.GeneratorCore/Generator/EnumTemplate.tt b/src/MessagePack.GeneratorCore/Generator/EnumTemplate.tt
index 28d34550..d9fda115 100644
--- a/src/MessagePack.GeneratorCore/Generator/EnumTemplate.tt
+++ b/src/MessagePack.GeneratorCore/Generator/EnumTemplate.tt
@@ -12,25 +12,21 @@
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1403 // File may only contain a single namespace
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace <#= Namespace #>
 {
-    using System;
-    using System.Buffers;
-    using MessagePack;
 <# foreach(var info in EnumSerializationInfos) { #>
 
     public sealed class <#= info.Name #>Formatter : global::MessagePack.Formatters.IMessagePackFormatter<<#= info.FullName #>>
     {
-        public void Serialize(ref MessagePackWriter writer, <#= info.FullName #> value, global::MessagePack.MessagePackSerializerOptions options)
+        public void Serialize(ref global::MessagePack.MessagePackWriter writer, <#= info.FullName #> value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            writer.Write((<#= info.UnderlyingType #>)value);
+            writer.Write((global::System.<#= info.UnderlyingType #>)value);
         }
 
-        public <#= info.FullName #> Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+        public <#= info.FullName #> Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             return (<#= info.FullName #>)reader.Read<#= info.UnderlyingType #>();
         }
@@ -43,6 +39,5 @@ namespace <#= Namespace #>
 #pragma warning restore 618
 #pragma warning restore 612
 
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1403 // File may only contain a single namespace
 #pragma warning restore SA1649 // File name should match first type name
diff --git a/src/MessagePack.GeneratorCore/Generator/FormatterTemplate.cs b/src/MessagePack.GeneratorCore/Generator/FormatterTemplate.cs
index e153d5eb..dfb84caf 100644
--- a/src/MessagePack.GeneratorCore/Generator/FormatterTemplate.cs
+++ b/src/MessagePack.GeneratorCore/Generator/FormatterTemplate.cs
@@ -35,7 +35,6 @@ namespace MessagePackCompiler.Generator
 #pragma warning disable 168
 
 #pragma warning disable SA1129 // Do not use default value type constructor
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1309 // Field names should not begin with underscore
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1403 // File may only contain a single namespace
@@ -43,10 +42,10 @@ namespace MessagePackCompiler.Generator
 
 namespace ");
             this.Write(this.ToStringHelper.ToStringWithCulture(Namespace));
-            this.Write("\r\n{\r\n    using global::System.Buffers;\r\n    using global::MessagePack;\r\n");
+            this.Write("\r\n{\r\n");
  foreach (var objInfo in ObjectSerializationInfos) {
     bool isFormatterResolverNecessary = ShouldUseFormatterResolverHelper.ShouldUseFormatterResolver(objInfo.Members);
-            this.Write("\r\n    public sealed class ");
+            this.Write("    public sealed class ");
             this.Write(this.ToStringHelper.ToStringWithCulture(objInfo.FormatterNameWithoutNameSpace));
             this.Write(" : global::MessagePack.Formatters.IMessagePackFormatter<");
             this.Write(this.ToStringHelper.ToStringWithCulture(objInfo.FullName));
@@ -205,7 +204,7 @@ namespace ");
  } 
             this.Write("            reader.Depth--;\r\n            return ____result;\r\n");
  } 
-            this.Write("        }\r\n    }\r\n");
+            this.Write("        }\r\n    }\r\n\r\n");
  } 
             this.Write(@"}
 
@@ -215,7 +214,6 @@ namespace ");
 #pragma warning restore 612
 
 #pragma warning restore SA1129 // Do not use default value type constructor
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1309 // Field names should not begin with underscore
 #pragma warning restore SA1312 // Variable names should begin with lower-case letter
 #pragma warning restore SA1403 // File may only contain a single namespace
diff --git a/src/MessagePack.GeneratorCore/Generator/FormatterTemplate.tt b/src/MessagePack.GeneratorCore/Generator/FormatterTemplate.tt
index 631dc9f1..bf96d9e5 100644
--- a/src/MessagePack.GeneratorCore/Generator/FormatterTemplate.tt
+++ b/src/MessagePack.GeneratorCore/Generator/FormatterTemplate.tt
@@ -13,7 +13,6 @@
 #pragma warning disable 168
 
 #pragma warning disable SA1129 // Do not use default value type constructor
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1309 // Field names should not begin with underscore
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1403 // File may only contain a single namespace
@@ -21,11 +20,8 @@
 
 namespace <#= Namespace #>
 {
-    using global::System.Buffers;
-    using global::MessagePack;
 <# foreach (var objInfo in ObjectSerializationInfos) {
     bool isFormatterResolverNecessary = ShouldUseFormatterResolverHelper.ShouldUseFormatterResolver(objInfo.Members);#>
-
     public sealed class <#= objInfo.FormatterNameWithoutNameSpace #> : global::MessagePack.Formatters.IMessagePackFormatter<<#= objInfo.FullName #>>
 <# foreach (var typeArg in objInfo.GenericTypeParameters.Where(x => x.HasConstraints)) { #>
         where <#= typeArg.Name #> : <#= typeArg.Constraints #>
@@ -155,8 +151,8 @@ namespace <#= Namespace #>
 <# } #>
         }
     }
-<# } #>
-}
+
+<# } #>}
 
 #pragma warning restore 168
 #pragma warning restore 414
@@ -164,7 +160,6 @@ namespace <#= Namespace #>
 #pragma warning restore 612
 
 #pragma warning restore SA1129 // Do not use default value type constructor
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1309 // Field names should not begin with underscore
 #pragma warning restore SA1312 // Variable names should begin with lower-case letter
 #pragma warning restore SA1403 // File may only contain a single namespace
diff --git a/src/MessagePack.GeneratorCore/Generator/ResolverTemplate.cs b/src/MessagePack.GeneratorCore/Generator/ResolverTemplate.cs
index 48e4df6b..c433e545 100644
--- a/src/MessagePack.GeneratorCore/Generator/ResolverTemplate.cs
+++ b/src/MessagePack.GeneratorCore/Generator/ResolverTemplate.cs
@@ -34,13 +34,12 @@ namespace MessagePackCompiler.Generator
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace ");
             this.Write(this.ToStringHelper.ToStringWithCulture(Namespace));
-            this.Write("\r\n{\r\n    using System;\r\n\r\n    public class ");
+            this.Write("\r\n{\r\n    public class ");
             this.Write(this.ToStringHelper.ToStringWithCulture(ResolverName));
             this.Write(" : global::MessagePack.IFormatterResolver\r\n    {\r\n        public static readonly " +
                     "global::MessagePack.IFormatterResolver Instance = new ");
@@ -76,10 +75,10 @@ namespace ");
     internal static class ");
             this.Write(this.ToStringHelper.ToStringWithCulture(ResolverName));
             this.Write("GetFormatterHelper\r\n    {\r\n        private static readonly global::System.Collect" +
-                    "ions.Generic.Dictionary<Type, int> lookup;\r\n\r\n        static ");
+                    "ions.Generic.Dictionary<global::System.Type, int> lookup;\r\n\r\n        static ");
             this.Write(this.ToStringHelper.ToStringWithCulture(ResolverName));
             this.Write("GetFormatterHelper()\r\n        {\r\n            lookup = new global::System.Collecti" +
-                    "ons.Generic.Dictionary<Type, int>(");
+                    "ons.Generic.Dictionary<global::System.Type, int>(");
             this.Write(this.ToStringHelper.ToStringWithCulture(RegisterInfos.Length));
             this.Write(")\r\n            {\r\n");
  for(var i = 0; i < RegisterInfos.Length; i++) { var x = RegisterInfos[i]; 
@@ -92,7 +91,7 @@ namespace ");
             this.Write(@"            };
         }
 
-        internal static object GetFormatter(Type t)
+        internal static object GetFormatter(global::System.Type t)
         {
             int key;
             if (!lookup.TryGetValue(t, out key))
@@ -122,7 +121,6 @@ namespace ");
 #pragma warning restore 612
 
 #pragma warning restore SA1312 // Variable names should begin with lower-case letter
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1649 // File name should match first type name
 ");
             return this.GenerationEnvironment.ToString();
diff --git a/src/MessagePack.GeneratorCore/Generator/ResolverTemplate.tt b/src/MessagePack.GeneratorCore/Generator/ResolverTemplate.tt
index e61688a1..1fcd9839 100644
--- a/src/MessagePack.GeneratorCore/Generator/ResolverTemplate.tt
+++ b/src/MessagePack.GeneratorCore/Generator/ResolverTemplate.tt
@@ -12,16 +12,11 @@
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace <#= Namespace #>
 {
-    using System;
-    using System.Buffers;
-    using MessagePack;
-
     public class <#= ResolverName #> : global::MessagePack.IFormatterResolver
     {
         public static readonly global::MessagePack.IFormatterResolver Instance = new <#= ResolverName #>();
@@ -52,11 +47,11 @@ namespace <#= Namespace #>
 
     internal static class <#= ResolverName #>GetFormatterHelper
     {
-        private static readonly global::System.Collections.Generic.Dictionary<Type, int> lookup;
+        private static readonly global::System.Collections.Generic.Dictionary<global::System.Type, int> lookup;
 
         static <#= ResolverName #>GetFormatterHelper()
         {
-            lookup = new global::System.Collections.Generic.Dictionary<Type, int>(<#= RegisterInfos.Length #>)
+            lookup = new global::System.Collections.Generic.Dictionary<global::System.Type, int>(<#= RegisterInfos.Length #>)
             {
 <# for(var i = 0; i < RegisterInfos.Length; i++) { var x = RegisterInfos[i]; #>
                 { typeof(<#= x.FullName #>), <#= i #> },
@@ -64,7 +59,7 @@ namespace <#= Namespace #>
             };
         }
 
-        internal static object GetFormatter(Type t)
+        internal static object GetFormatter(global::System.Type t)
         {
             int key;
             if (!lookup.TryGetValue(t, out key))
@@ -75,7 +70,7 @@ namespace <#= Namespace #>
             switch (key)
             {
 <# for(var i = 0; i < RegisterInfos.Length; i++) { var x = RegisterInfos[i]; #>
-                case <#= i #>: return new <#= x.FormatterName.StartsWith("global::") ? x.FormatterName: (!string.IsNullOrEmpty(FormatterNamespace) ? FormatterNamespace + "." : FormatterNamespace) + x.FormatterName#>();
+                case <#= i #>: return new <#= x.FormatterName.StartsWith("global::") ? x.FormatterName: (!string.IsNullOrEmpty(FormatterNamespace) ? FormatterNamespace + "." : FormatterNamespace) + x.FormatterName #>();
 <# } #>
                 default: return null;
             }
@@ -89,5 +84,4 @@ namespace <#= Namespace #>
 #pragma warning restore 612
 
 #pragma warning restore SA1312 // Variable names should begin with lower-case letter
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1649 // File name should match first type name
diff --git a/src/MessagePack.GeneratorCore/Generator/StringKey/StringKeyFormatterTemplate.cs b/src/MessagePack.GeneratorCore/Generator/StringKey/StringKeyFormatterTemplate.cs
index a3df9f44..d598c202 100644
--- a/src/MessagePack.GeneratorCore/Generator/StringKey/StringKeyFormatterTemplate.cs
+++ b/src/MessagePack.GeneratorCore/Generator/StringKey/StringKeyFormatterTemplate.cs
@@ -35,7 +35,6 @@ namespace MessagePackCompiler.Generator
 #pragma warning disable 168
 
 #pragma warning disable SA1129 // Do not use default value type constructor
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1309 // Field names should not begin with underscore
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1403 // File may only contain a single namespace
@@ -43,7 +42,7 @@ namespace MessagePackCompiler.Generator
 
 namespace ");
             this.Write(this.ToStringHelper.ToStringWithCulture(Namespace));
-            this.Write("\r\n{\r\n    using global::System.Buffers;\r\n    using global::MessagePack;\r\n");
+            this.Write("\r\n{\r\n");
  var list = new List<ValueTuple<MemberSerializationInfo, byte[]>>();
 foreach (var objInfo in ObjectSerializationInfos) {
     list.Clear();
@@ -53,7 +52,7 @@ foreach (var objInfo in ObjectSerializationInfos) {
     }
 
     bool isFormatterResolverNecessary = ShouldUseFormatterResolverHelper.ShouldUseFormatterResolver(objInfo.Members); 
-            this.Write("\r\n    public sealed class ");
+            this.Write("    public sealed class ");
             this.Write(this.ToStringHelper.ToStringWithCulture(objInfo.FormatterNameWithoutNameSpace));
             this.Write(" : global::MessagePack.Formatters.IMessagePackFormatter<");
             this.Write(this.ToStringHelper.ToStringWithCulture(objInfo.FullName));
@@ -191,9 +190,21 @@ foreach (var objInfo in ObjectSerializationInfos) {
  if (objInfo.Members.Length != 0) { 
             this.Write("            reader.Depth--;\r\n");
  } 
-            this.Write("            return ____result;\r\n        }\r\n    }\r\n");
+            this.Write("            return ____result;\r\n        }\r\n    }\r\n\r\n");
  } 
-            this.Write("}\r\n");
+            this.Write(@"}
+
+#pragma warning restore 168
+#pragma warning restore 414
+#pragma warning restore 618
+#pragma warning restore 612
+
+#pragma warning restore SA1129 // Do not use default value type constructor
+#pragma warning restore SA1309 // Field names should not begin with underscore
+#pragma warning restore SA1312 // Variable names should begin with lower-case letter
+#pragma warning restore SA1403 // File may only contain a single namespace
+#pragma warning restore SA1649 // File name should match first type name
+");
             return this.GenerationEnvironment.ToString();
         }
     }
diff --git a/src/MessagePack.GeneratorCore/Generator/StringKey/StringKeyFormatterTemplate.tt b/src/MessagePack.GeneratorCore/Generator/StringKey/StringKeyFormatterTemplate.tt
index 9bc3e4d8..296ef454 100644
--- a/src/MessagePack.GeneratorCore/Generator/StringKey/StringKeyFormatterTemplate.tt
+++ b/src/MessagePack.GeneratorCore/Generator/StringKey/StringKeyFormatterTemplate.tt
@@ -14,7 +14,6 @@
 #pragma warning disable 168
 
 #pragma warning disable SA1129 // Do not use default value type constructor
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1309 // Field names should not begin with underscore
 #pragma warning disable SA1312 // Variable names should begin with lower-case letter
 #pragma warning disable SA1403 // File may only contain a single namespace
@@ -22,8 +21,6 @@
 
 namespace <#= Namespace #>
 {
-    using global::System.Buffers;
-    using global::MessagePack;
 <# var list = new List<ValueTuple<MemberSerializationInfo, byte[]>>();
 foreach (var objInfo in ObjectSerializationInfos) {
     list.Clear();
@@ -33,7 +30,6 @@ foreach (var objInfo in ObjectSerializationInfos) {
     }
 
     bool isFormatterResolverNecessary = ShouldUseFormatterResolverHelper.ShouldUseFormatterResolver(objInfo.Members); #>
-
     public sealed class <#= objInfo.FormatterNameWithoutNameSpace #> : global::MessagePack.Formatters.IMessagePackFormatter<<#= objInfo.FullName #>>
 <# foreach (var typeArg in objInfo.GenericTypeParameters.Where(x => x.HasConstraints)) {#>
         where <#= typeArg.Name #> : <#= typeArg.Constraints #>
@@ -147,5 +143,16 @@ foreach (var objInfo in ObjectSerializationInfos) {
             return ____result;
         }
     }
-<# } #>
-}
+
+<# } #>}
+
+#pragma warning restore 168
+#pragma warning restore 414
+#pragma warning restore 618
+#pragma warning restore 612
+
+#pragma warning restore SA1129 // Do not use default value type constructor
+#pragma warning restore SA1309 // Field names should not begin with underscore
+#pragma warning restore SA1312 // Variable names should begin with lower-case letter
+#pragma warning restore SA1403 // File may only contain a single namespace
+#pragma warning restore SA1649 // File name should match first type name
diff --git a/src/MessagePack.GeneratorCore/Generator/UnionTemplate.cs b/src/MessagePack.GeneratorCore/Generator/UnionTemplate.cs
index 1106f1cb..6ea73cff 100644
--- a/src/MessagePack.GeneratorCore/Generator/UnionTemplate.cs
+++ b/src/MessagePack.GeneratorCore/Generator/UnionTemplate.cs
@@ -34,38 +34,41 @@ namespace MessagePackCompiler.Generator
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1403 // File may only contain a single namespace
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace ");
             this.Write(this.ToStringHelper.ToStringWithCulture(Namespace));
-            this.Write("\r\n{\r\n    using System;\r\n    using System.Buffers;\r\n    using System.Collections.G" +
-                    "eneric;\r\n    using MessagePack;\r\n\r\n");
+            this.Write("\r\n{\r\n");
  foreach(var info in UnionSerializationInfos) { 
             this.Write("    public sealed class ");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.Name));
             this.Write("Formatter : global::MessagePack.Formatters.IMessagePackFormatter<");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.FullName));
-            this.Write(">\r\n    {\r\n        private readonly Dictionary<RuntimeTypeHandle, KeyValuePair<int" +
-                    ", int>> typeToKeyAndJumpMap;\r\n        private readonly Dictionary<int, int> keyT" +
-                    "oJumpMap;\r\n\r\n        public ");
+            this.Write(@">
+    {
+        private readonly global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>> typeToKeyAndJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<int, int> keyToJumpMap;
+
+        public ");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.Name));
-            this.Write("Formatter()\r\n        {\r\n            this.typeToKeyAndJumpMap = new Dictionary<Run" +
-                    "timeTypeHandle, KeyValuePair<int, int>>(");
+            this.Write("Formatter()\r\n        {\r\n            this.typeToKeyAndJumpMap = new global::System" +
+                    ".Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System" +
+                    ".Collections.Generic.KeyValuePair<int, int>>(");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.SubTypes.Length));
             this.Write(", global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)\r\n      " +
                     "      {\r\n");
  for(var i = 0; i < info.SubTypes.Length; i++) { var item = info.SubTypes[i]; 
             this.Write("                { typeof(");
             this.Write(this.ToStringHelper.ToStringWithCulture(item.Type));
-            this.Write(").TypeHandle, new KeyValuePair<int, int>(");
+            this.Write(").TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(");
             this.Write(this.ToStringHelper.ToStringWithCulture(item.Key));
             this.Write(", ");
             this.Write(this.ToStringHelper.ToStringWithCulture(i));
             this.Write(") },\r\n");
  } 
-            this.Write("            };\r\n            this.keyToJumpMap = new Dictionary<int, int>(");
+            this.Write("            };\r\n            this.keyToJumpMap = new global::System.Collections.Ge" +
+                    "neric.Dictionary<int, int>(");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.SubTypes.Length));
             this.Write(")\r\n            {\r\n");
  for(var i = 0; i < info.SubTypes.Length; i++) { var item = info.SubTypes[i]; 
@@ -75,12 +78,12 @@ namespace ");
             this.Write(this.ToStringHelper.ToStringWithCulture(i));
             this.Write(" },\r\n");
  } 
-            this.Write("            };\r\n        }\r\n\r\n        public void Serialize(ref MessagePackWriter " +
-                    "writer, ");
+            this.Write("            };\r\n        }\r\n\r\n        public void Serialize(ref global::MessagePac" +
+                    "k.MessagePackWriter writer, ");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.FullName));
             this.Write(@" value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            KeyValuePair<int, int> keyValuePair;
+            global::System.Collections.Generic.KeyValuePair<int, int> keyValuePair;
             if (value != null && this.typeToKeyAndJumpMap.TryGetValue(value.GetType().TypeHandle, out keyValuePair))
             {
                 writer.WriteArrayHeader(2);
@@ -101,7 +104,7 @@ namespace ");
                     "\r\n                return;\r\n            }\r\n\r\n            writer.WriteNil();\r\n    " +
                     "    }\r\n\r\n        public ");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.FullName));
-            this.Write(@" Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+            this.Write(@" Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             if (reader.TryReadNil())
             {
@@ -110,7 +113,7 @@ namespace ");
 
             if (reader.ReadArrayHeader() != 2)
             {
-                throw new InvalidOperationException(""Invalid Union data was detected. Type:");
+                throw new global::System.InvalidOperationException(""Invalid Union data was detected. Type:");
             this.Write(this.ToStringHelper.ToStringWithCulture(info.FullName));
             this.Write("\");\r\n            }\r\n\r\n            options.Security.DepthStep(ref reader);\r\n      " +
                     "      var key = reader.ReadInt32();\r\n\r\n            if (!this.keyToJumpMap.TryGet" +
@@ -139,7 +142,6 @@ namespace ");
 #pragma warning restore 618
 #pragma warning restore 612
 
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1403 // File may only contain a single namespace
 #pragma warning restore SA1649 // File name should match first type name
 ");
diff --git a/src/MessagePack.GeneratorCore/Generator/UnionTemplate.tt b/src/MessagePack.GeneratorCore/Generator/UnionTemplate.tt
index 216cf3c3..174dd3d2 100644
--- a/src/MessagePack.GeneratorCore/Generator/UnionTemplate.tt
+++ b/src/MessagePack.GeneratorCore/Generator/UnionTemplate.tt
@@ -12,32 +12,26 @@
 #pragma warning disable 414
 #pragma warning disable 168
 
-#pragma warning disable SA1200 // Using directives should be placed correctly
 #pragma warning disable SA1403 // File may only contain a single namespace
 #pragma warning disable SA1649 // File name should match first type name
 
 namespace <#= Namespace #>
 {
-    using System;
-    using System.Buffers;
-    using System.Collections.Generic;
-    using MessagePack;
-
 <# foreach(var info in UnionSerializationInfos) { #>
     public sealed class <#= info.Name #>Formatter : global::MessagePack.Formatters.IMessagePackFormatter<<#= info.FullName #>>
     {
-        private readonly Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>> typeToKeyAndJumpMap;
-        private readonly Dictionary<int, int> keyToJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>> typeToKeyAndJumpMap;
+        private readonly global::System.Collections.Generic.Dictionary<int, int> keyToJumpMap;
 
         public <#= info.Name #>Formatter()
         {
-            this.typeToKeyAndJumpMap = new Dictionary<RuntimeTypeHandle, KeyValuePair<int, int>>(<#= info.SubTypes.Length #>, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
+            this.typeToKeyAndJumpMap = new global::System.Collections.Generic.Dictionary<global::System.RuntimeTypeHandle, global::System.Collections.Generic.KeyValuePair<int, int>>(<#= info.SubTypes.Length #>, global::MessagePack.Internal.RuntimeTypeHandleEqualityComparer.Default)
             {
 <# for(var i = 0; i < info.SubTypes.Length; i++) { var item = info.SubTypes[i]; #>
-                { typeof(<#= item.Type #>).TypeHandle, new KeyValuePair<int, int>(<#= item.Key #>, <#= i #>) },
+                { typeof(<#= item.Type #>).TypeHandle, new global::System.Collections.Generic.KeyValuePair<int, int>(<#= item.Key #>, <#= i #>) },
 <# } #>
             };
-            this.keyToJumpMap = new Dictionary<int, int>(<#= info.SubTypes.Length #>)
+            this.keyToJumpMap = new global::System.Collections.Generic.Dictionary<int, int>(<#= info.SubTypes.Length #>)
             {
 <# for(var i = 0; i < info.SubTypes.Length; i++) { var item = info.SubTypes[i]; #>
                 { <#= item.Key #>, <#= i #> },
@@ -45,9 +39,9 @@ namespace <#= Namespace #>
             };
         }
 
-        public void Serialize(ref MessagePackWriter writer, <#= info.FullName #> value, global::MessagePack.MessagePackSerializerOptions options)
+        public void Serialize(ref global::MessagePack.MessagePackWriter writer, <#= info.FullName #> value, global::MessagePack.MessagePackSerializerOptions options)
         {
-            KeyValuePair<int, int> keyValuePair;
+            global::System.Collections.Generic.KeyValuePair<int, int> keyValuePair;
             if (value != null && this.typeToKeyAndJumpMap.TryGetValue(value.GetType().TypeHandle, out keyValuePair))
             {
                 writer.WriteArrayHeader(2);
@@ -69,7 +63,7 @@ namespace <#= Namespace #>
             writer.WriteNil();
         }
 
-        public <#= info.FullName #> Deserialize(ref MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
+        public <#= info.FullName #> Deserialize(ref global::MessagePack.MessagePackReader reader, global::MessagePack.MessagePackSerializerOptions options)
         {
             if (reader.TryReadNil())
             {
@@ -78,7 +72,7 @@ namespace <#= Namespace #>
 
             if (reader.ReadArrayHeader() != 2)
             {
-                throw new InvalidOperationException("Invalid Union data was detected. Type:<#= info.FullName #>");
+                throw new global::System.InvalidOperationException("Invalid Union data was detected. Type:<#= info.FullName #>");
             }
 
             options.Security.DepthStep(ref reader);
@@ -116,6 +110,5 @@ namespace <#= Namespace #>
 #pragma warning restore 618
 #pragma warning restore 612
 
-#pragma warning restore SA1200 // Using directives should be placed correctly
 #pragma warning restore SA1403 // File may only contain a single namespace
 #pragma warning restore SA1649 // File name should match first type name