diff --git a/package-lock.json b/package-lock.json
index 3b14ca1..51f089a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -11,6 +11,7 @@
       "devDependencies": {
         "@github/prettier-config": "^0.0.4",
         "@lhci/cli": "^0.7.0",
+        "@open-wc/testing": "^3.1.2",
         "@typescript-eslint/eslint-plugin": "^5.16.0",
         "@typescript-eslint/parser": "^5.16.0",
         "@web/test-runner": "^0.13.27",
@@ -26,6 +27,7 @@
         "karma-mocha": "^2.0.1",
         "karma-mocha-reporter": "^2.2.5",
         "mocha": "^8.3.0",
+        "sinon": "^13.0.1",
         "tslib": "^2.3.1",
         "typescript": "^4.6.3"
       }
@@ -117,6 +119,15 @@
         "js-yaml": "bin/js-yaml.js"
       }
     },
+    "node_modules/@esm-bundle/chai": {
+      "version": "4.3.4",
+      "resolved": "https://registry.npmjs.org/@esm-bundle/chai/-/chai-4.3.4.tgz",
+      "integrity": "sha512-6Tx35wWiNw7X0nLY9RMx8v3EL8SacCFW+eEZOE9Hc+XxmU5HFE2AFEg+GehUZpiyDGwVvPH75ckGlqC7coIPnA==",
+      "dev": true,
+      "dependencies": {
+        "@types/chai": "^4.2.12"
+      }
+    },
     "node_modules/@github/prettier-config": {
       "version": "0.0.4",
       "resolved": "https://registry.npmjs.org/@github/prettier-config/-/prettier-config-0.0.4.tgz",
@@ -204,6 +215,12 @@
         "tree-kill": "^1.2.1"
       }
     },
+    "node_modules/@lit/reactive-element": {
+      "version": "1.3.1",
+      "resolved": "https://registry.npmjs.org/@lit/reactive-element/-/reactive-element-1.3.1.tgz",
+      "integrity": "sha512-nOJARIr3pReqK3hfFCSW2Zg/kFcFsSAlIE7z4a0C9D2dPrgD/YSn3ZP2ET/rxKB65SXyG7jJbkynBRm+tGlacw==",
+      "dev": true
+    },
     "node_modules/@nodelib/fs.scandir": {
       "version": "2.1.5",
       "resolved": "https://registry.npmjs.org/@nodelib/fs.scandir/-/fs.scandir-2.1.5.tgz",
@@ -239,6 +256,101 @@
         "node": ">= 8"
       }
     },
+    "node_modules/@open-wc/chai-dom-equals": {
+      "version": "0.12.36",
+      "resolved": "https://registry.npmjs.org/@open-wc/chai-dom-equals/-/chai-dom-equals-0.12.36.tgz",
+      "integrity": "sha512-Gt1fa37h4rtWPQGETSU4n1L678NmMi9KwHM1sH+JCGcz45rs8DBPx7MUVeGZ+HxRlbEI5t9LU2RGGv6xT2OlyA==",
+      "dev": true,
+      "dependencies": {
+        "@open-wc/semantic-dom-diff": "^0.13.16",
+        "@types/chai": "^4.1.7"
+      }
+    },
+    "node_modules/@open-wc/chai-dom-equals/node_modules/@open-wc/semantic-dom-diff": {
+      "version": "0.13.21",
+      "resolved": "https://registry.npmjs.org/@open-wc/semantic-dom-diff/-/semantic-dom-diff-0.13.21.tgz",
+      "integrity": "sha512-BONpjHcGX2zFa9mfnwBCLEmlDsOHzT+j6Qt1yfK3MzFXFtAykfzFjAgaxPetu0YbBlCfXuMlfxI4vlRGCGMvFg==",
+      "dev": true
+    },
+    "node_modules/@open-wc/dedupe-mixin": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/@open-wc/dedupe-mixin/-/dedupe-mixin-1.3.0.tgz",
+      "integrity": "sha512-UfdK1MPnR6T7f3svzzYBfu3qBkkZ/KsPhcpc3JYhsUY4hbpwNF9wEQtD4Z+/mRqMTJrKg++YSxIxE0FBhY3RIw==",
+      "dev": true
+    },
+    "node_modules/@open-wc/scoped-elements": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/@open-wc/scoped-elements/-/scoped-elements-2.0.1.tgz",
+      "integrity": "sha512-JS6ozxUFwFX3+Er91v9yQzNIaFn7OnE0iESKTbFvkkKdNwvAPtp1fpckBKIvWk8Ae9ZcoI9DYZuT2DDbMPcadA==",
+      "dev": true,
+      "dependencies": {
+        "@lit/reactive-element": "^1.0.0",
+        "@open-wc/dedupe-mixin": "^1.3.0",
+        "@webcomponents/scoped-custom-element-registry": "^0.0.3"
+      }
+    },
+    "node_modules/@open-wc/semantic-dom-diff": {
+      "version": "0.19.5",
+      "resolved": "https://registry.npmjs.org/@open-wc/semantic-dom-diff/-/semantic-dom-diff-0.19.5.tgz",
+      "integrity": "sha512-Wi0Fuj3dzqlWClU0y+J4k/nqTcH0uwgOWxZXPyeyG3DdvuyyjgiT4L4I/s6iVShWQvvEsyXnj7yVvixAo3CZvg==",
+      "dev": true,
+      "dependencies": {
+        "@types/chai": "^4.2.11",
+        "@web/test-runner-commands": "^0.5.7"
+      }
+    },
+    "node_modules/@open-wc/semantic-dom-diff/node_modules/@web/test-runner-commands": {
+      "version": "0.5.13",
+      "resolved": "https://registry.npmjs.org/@web/test-runner-commands/-/test-runner-commands-0.5.13.tgz",
+      "integrity": "sha512-FXnpUU89ALbRlh9mgBd7CbSn5uzNtr8gvnQZPOvGLDAJ7twGvZdUJEAisPygYx2BLPSFl3/Mre8pH8zshJb8UQ==",
+      "dev": true,
+      "dependencies": {
+        "@web/test-runner-core": "^0.10.20",
+        "mkdirp": "^1.0.4"
+      },
+      "engines": {
+        "node": ">=12.0.0"
+      }
+    },
+    "node_modules/@open-wc/semantic-dom-diff/node_modules/mkdirp": {
+      "version": "1.0.4",
+      "resolved": "https://registry.npmjs.org/mkdirp/-/mkdirp-1.0.4.tgz",
+      "integrity": "sha512-vVqVZQyf3WLx2Shd0qJ9xuvqgAyKPLAiqITEtqW0oIUjzo3PePDd6fW9iFz30ef7Ysp/oiWqbhszeGWW2T6Gzw==",
+      "dev": true,
+      "bin": {
+        "mkdirp": "bin/cmd.js"
+      },
+      "engines": {
+        "node": ">=10"
+      }
+    },
+    "node_modules/@open-wc/testing": {
+      "version": "3.1.2",
+      "resolved": "https://registry.npmjs.org/@open-wc/testing/-/testing-3.1.2.tgz",
+      "integrity": "sha512-2KjEszLItrIEZwCLFjWOSy4rnLzLOpgckrKfZjNA39PpFR3xD9bqYU30TTnLRHBk2B/0ZUbHglyca3iwcF964w==",
+      "dev": true,
+      "dependencies": {
+        "@esm-bundle/chai": "^4.3.4",
+        "@open-wc/chai-dom-equals": "^0.12.36",
+        "@open-wc/semantic-dom-diff": "^0.19.5",
+        "@open-wc/testing-helpers": "^2.1.2",
+        "@types/chai": "^4.2.11",
+        "@types/chai-dom": "^0.0.9",
+        "@types/sinon-chai": "^3.2.3",
+        "chai-a11y-axe": "^1.3.2"
+      }
+    },
+    "node_modules/@open-wc/testing-helpers": {
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/@open-wc/testing-helpers/-/testing-helpers-2.1.2.tgz",
+      "integrity": "sha512-NEdsV47DnOWaw3Wpp85p4qZ6bdubtGPdlTiblk8vSf2HJ2sR4b3ckyRWzsj/k+pcxrDGt8z0Awz71p+048Rrfg==",
+      "dev": true,
+      "dependencies": {
+        "@open-wc/scoped-elements": "^2.0.1",
+        "lit": "^2.0.0",
+        "lit-html": "^2.0.0"
+      }
+    },
     "node_modules/@rollup/plugin-node-resolve": {
       "version": "11.2.1",
       "resolved": "https://registry.npmjs.org/@rollup/plugin-node-resolve/-/plugin-node-resolve-11.2.1.tgz",
@@ -285,6 +397,41 @@
         "node": ">=6"
       }
     },
+    "node_modules/@sinonjs/commons": {
+      "version": "1.8.3",
+      "resolved": "https://registry.npmjs.org/@sinonjs/commons/-/commons-1.8.3.tgz",
+      "integrity": "sha512-xkNcLAn/wZaX14RPlwizcKicDk9G3F8m2nU3L7Ukm5zBgTwiT0wsoFAHx9Jq56fJA1z/7uKGtCRu16sOUCLIHQ==",
+      "dev": true,
+      "dependencies": {
+        "type-detect": "4.0.8"
+      }
+    },
+    "node_modules/@sinonjs/fake-timers": {
+      "version": "9.1.1",
+      "resolved": "https://registry.npmjs.org/@sinonjs/fake-timers/-/fake-timers-9.1.1.tgz",
+      "integrity": "sha512-Wp5vwlZ0lOqpSYGKqr53INws9HLkt6JDc/pDZcPf7bchQnrXJMXPns8CXx0hFikMSGSWfvtvvpb2gtMVfkWagA==",
+      "dev": true,
+      "dependencies": {
+        "@sinonjs/commons": "^1.7.0"
+      }
+    },
+    "node_modules/@sinonjs/samsam": {
+      "version": "6.1.1",
+      "resolved": "https://registry.npmjs.org/@sinonjs/samsam/-/samsam-6.1.1.tgz",
+      "integrity": "sha512-cZ7rKJTLiE7u7Wi/v9Hc2fs3Ucc3jrWeMgPHbbTCeVAB2S0wOBbYlkJVeNSL04i7fdhT8wIbDq1zhC/PXTD2SA==",
+      "dev": true,
+      "dependencies": {
+        "@sinonjs/commons": "^1.6.0",
+        "lodash.get": "^4.4.2",
+        "type-detect": "^4.0.8"
+      }
+    },
+    "node_modules/@sinonjs/text-encoding": {
+      "version": "0.7.1",
+      "resolved": "https://registry.npmjs.org/@sinonjs/text-encoding/-/text-encoding-0.7.1.tgz",
+      "integrity": "sha512-+iTbntw2IZPb/anVDbypzfQa+ay64MW0Zo8aJ8gZPWMMK6/OubMVb6lUPMagqjOPnmtauXnFCACVl3O7ogjeqQ==",
+      "dev": true
+    },
     "node_modules/@socket.io/base64-arraybuffer": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/@socket.io/base64-arraybuffer/-/base64-arraybuffer-1.0.2.tgz",
@@ -343,6 +490,21 @@
         "@types/responselike": "*"
       }
     },
+    "node_modules/@types/chai": {
+      "version": "4.3.0",
+      "resolved": "https://registry.npmjs.org/@types/chai/-/chai-4.3.0.tgz",
+      "integrity": "sha512-/ceqdqeRraGolFTcfoXNiqjyQhZzbINDngeoAq9GoHa8PPK1yNzTaxWjA6BFWp5Ua9JpXEMSS4s5i9tS0hOJtw==",
+      "dev": true
+    },
+    "node_modules/@types/chai-dom": {
+      "version": "0.0.9",
+      "resolved": "https://registry.npmjs.org/@types/chai-dom/-/chai-dom-0.0.9.tgz",
+      "integrity": "sha512-jj4F2NJog2/GBYsyJ8+NvhnWUBbPY4MUAKLdPJE6+568rw12GGXvj0ycUuP5nndVrnJgozmJAoMTvxvjJATXWw==",
+      "dev": true,
+      "dependencies": {
+        "@types/chai": "*"
+      }
+    },
     "node_modules/@types/co-body": {
       "version": "6.1.0",
       "resolved": "https://registry.npmjs.org/@types/co-body/-/co-body-6.1.0.tgz",
@@ -603,6 +765,37 @@
         "@types/node": "*"
       }
     },
+    "node_modules/@types/sinon": {
+      "version": "10.0.11",
+      "resolved": "https://registry.npmjs.org/@types/sinon/-/sinon-10.0.11.tgz",
+      "integrity": "sha512-dmZsHlBsKUtBpHriNjlK0ndlvEh8dcb9uV9Afsbt89QIyydpC7NcR+nWlAhASfy3GHnxTl4FX/aKE7XZUt/B4g==",
+      "dev": true,
+      "dependencies": {
+        "@types/sinonjs__fake-timers": "*"
+      }
+    },
+    "node_modules/@types/sinon-chai": {
+      "version": "3.2.8",
+      "resolved": "https://registry.npmjs.org/@types/sinon-chai/-/sinon-chai-3.2.8.tgz",
+      "integrity": "sha512-d4ImIQbT/rKMG8+AXpmcan5T2/PNeSjrYhvkwet6z0p8kzYtfgA32xzOBlbU0yqJfq+/0Ml805iFoODO0LP5/g==",
+      "dev": true,
+      "dependencies": {
+        "@types/chai": "*",
+        "@types/sinon": "*"
+      }
+    },
+    "node_modules/@types/sinonjs__fake-timers": {
+      "version": "8.1.2",
+      "resolved": "https://registry.npmjs.org/@types/sinonjs__fake-timers/-/sinonjs__fake-timers-8.1.2.tgz",
+      "integrity": "sha512-9GcLXF0/v3t80caGs5p2rRfkB+a8VBGLJZVih6CNFkx8IZ994wiKKLSRs9nuFwk1HevWs/1mnUmkApGrSGsShA==",
+      "dev": true
+    },
+    "node_modules/@types/trusted-types": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/@types/trusted-types/-/trusted-types-2.0.2.tgz",
+      "integrity": "sha512-F5DIZ36YVLE+PN+Zwws4kJogq47hNgX3Nx6WyDJ3kcplxyke3XIzB8uK5n/Lpm1HBsbGzd6nmGehL8cPekP+Tg==",
+      "dev": true
+    },
     "node_modules/@types/ws": {
       "version": "7.4.7",
       "resolved": "https://registry.npmjs.org/@types/ws/-/ws-7.4.7.tgz",
@@ -1275,6 +1468,12 @@
         "node": ">= 8"
       }
     },
+    "node_modules/@webcomponents/scoped-custom-element-registry": {
+      "version": "0.0.3",
+      "resolved": "https://registry.npmjs.org/@webcomponents/scoped-custom-element-registry/-/scoped-custom-element-registry-0.0.3.tgz",
+      "integrity": "sha512-lpSzgDCGbM99dytb3+J3Suo4+Bk1E13MPnWB42JK8GwxSAxFz+tC7TTv2hhDSIE2IirGNKNKCf3m08ecu6eAsQ==",
+      "dev": true
+    },
     "node_modules/accepts": {
       "version": "1.3.7",
       "resolved": "https://registry.npmjs.org/accepts/-/accepts-1.3.7.tgz",
@@ -2076,6 +2275,24 @@
         "node": ">=8"
       }
     },
+    "node_modules/chai-a11y-axe": {
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/chai-a11y-axe/-/chai-a11y-axe-1.4.0.tgz",
+      "integrity": "sha512-m7J6DVAl1ePL2ifPKHmwQyHXdCZ+Qfv+qduh6ScqcDfBnJEzpV1K49TblujM45j1XciZOFeFNqMb2sShXMg/mw==",
+      "dev": true,
+      "dependencies": {
+        "axe-core": "^4.3.3"
+      }
+    },
+    "node_modules/chai-a11y-axe/node_modules/axe-core": {
+      "version": "4.4.1",
+      "resolved": "https://registry.npmjs.org/axe-core/-/axe-core-4.4.1.tgz",
+      "integrity": "sha512-gd1kmb21kwNuWr6BQz8fv6GNECPBnUasepcoLbekws23NVBLODdsClRZ+bQ8+9Uomf3Sm3+Vwn0oYG9NvwnJCw==",
+      "dev": true,
+      "engines": {
+        "node": ">=4"
+      }
+    },
     "node_modules/chai-spies": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/chai-spies/-/chai-spies-1.0.0.tgz",
@@ -5777,6 +5994,12 @@
         "node": "*"
       }
     },
+    "node_modules/just-extend": {
+      "version": "4.2.1",
+      "resolved": "https://registry.npmjs.org/just-extend/-/just-extend-4.2.1.tgz",
+      "integrity": "sha512-g3UB796vUFIY90VIv/WX3L2c8CS2MdWUww3CNrYmqza1Fg0DURc2K/O4YrnklBdQarSJ/y8JnJYDGc+1iumQjg==",
+      "dev": true
+    },
     "node_modules/karma": {
       "version": "6.3.16",
       "resolved": "https://registry.npmjs.org/karma/-/karma-6.3.16.tgz",
@@ -6504,6 +6727,36 @@
         "node": ">=10"
       }
     },
+    "node_modules/lit": {
+      "version": "2.2.1",
+      "resolved": "https://registry.npmjs.org/lit/-/lit-2.2.1.tgz",
+      "integrity": "sha512-dSe++R50JqrvNGXmI9OE13de1z5U/Y3J2dTm/9GC86vedI8ILoR8ZGnxfThFpvQ9m0lR0qRnIR4IiKj/jDCfYw==",
+      "dev": true,
+      "dependencies": {
+        "@lit/reactive-element": "^1.3.0",
+        "lit-element": "^3.2.0",
+        "lit-html": "^2.2.0"
+      }
+    },
+    "node_modules/lit-element": {
+      "version": "3.2.0",
+      "resolved": "https://registry.npmjs.org/lit-element/-/lit-element-3.2.0.tgz",
+      "integrity": "sha512-HbE7yt2SnUtg5DCrWt028oaU4D5F4k/1cntAFHTkzY8ZIa8N0Wmu92PxSxucsQSOXlODFrICkQ5x/tEshKi13g==",
+      "dev": true,
+      "dependencies": {
+        "@lit/reactive-element": "^1.3.0",
+        "lit-html": "^2.2.0"
+      }
+    },
+    "node_modules/lit-html": {
+      "version": "2.2.1",
+      "resolved": "https://registry.npmjs.org/lit-html/-/lit-html-2.2.1.tgz",
+      "integrity": "sha512-AiJ/Rs0awjICs2FioTnHSh+Np5dhYSkyRczKy3wKjp8qjLhr1Ov+GiHrUQNdX8ou1LMuznpIME990AZsa/tR8g==",
+      "dev": true,
+      "dependencies": {
+        "@types/trusted-types": "^2.0.2"
+      }
+    },
     "node_modules/locate-path": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/locate-path/-/locate-path-2.0.0.tgz",
@@ -7248,6 +7501,34 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/nise": {
+      "version": "5.1.1",
+      "resolved": "https://registry.npmjs.org/nise/-/nise-5.1.1.tgz",
+      "integrity": "sha512-yr5kW2THW1AkxVmCnKEh4nbYkJdB3I7LUkiUgOvEkOp414mc2UMaHMA7pjq1nYowhdoJZGwEKGaQVbxfpWj10A==",
+      "dev": true,
+      "dependencies": {
+        "@sinonjs/commons": "^1.8.3",
+        "@sinonjs/fake-timers": ">=5",
+        "@sinonjs/text-encoding": "^0.7.1",
+        "just-extend": "^4.0.2",
+        "path-to-regexp": "^1.7.0"
+      }
+    },
+    "node_modules/nise/node_modules/isarray": {
+      "version": "0.0.1",
+      "resolved": "https://registry.npmjs.org/isarray/-/isarray-0.0.1.tgz",
+      "integrity": "sha1-ihis/Kmo9Bd+Cav8YDiTmwXR7t8=",
+      "dev": true
+    },
+    "node_modules/nise/node_modules/path-to-regexp": {
+      "version": "1.8.0",
+      "resolved": "https://registry.npmjs.org/path-to-regexp/-/path-to-regexp-1.8.0.tgz",
+      "integrity": "sha512-n43JRhlUKUAlibEJhPeir1ncUID16QnEjNpwzNdO3Lm4ywrBpBZ5oLD0I6br9evr1Y9JTqwRtAh7JLoOzAQdVA==",
+      "dev": true,
+      "dependencies": {
+        "isarray": "0.0.1"
+      }
+    },
     "node_modules/node-fetch": {
       "version": "2.6.7",
       "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.6.7.tgz",
@@ -8729,6 +9010,45 @@
       "integrity": "sha512-VUJ49FC8U1OxwZLxIbTTrDvLnf/6TDgxZcK8wxR8zs13xpx7xbG60ndBlhNrFi2EMuFRoeDoJO7wthSLq42EjA==",
       "dev": true
     },
+    "node_modules/sinon": {
+      "version": "13.0.1",
+      "resolved": "https://registry.npmjs.org/sinon/-/sinon-13.0.1.tgz",
+      "integrity": "sha512-8yx2wIvkBjIq/MGY1D9h1LMraYW+z1X0mb648KZnKSdvLasvDu7maa0dFaNYdTDczFgbjNw2tOmWdTk9saVfwQ==",
+      "dev": true,
+      "dependencies": {
+        "@sinonjs/commons": "^1.8.3",
+        "@sinonjs/fake-timers": "^9.0.0",
+        "@sinonjs/samsam": "^6.1.1",
+        "diff": "^5.0.0",
+        "nise": "^5.1.1",
+        "supports-color": "^7.2.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/sinon"
+      }
+    },
+    "node_modules/sinon/node_modules/has-flag": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/has-flag/-/has-flag-4.0.0.tgz",
+      "integrity": "sha512-EykJT/Q1KjTWctppgIAgfSO0tKVuZUjhgMr17kqTumMl6Afv3EISleU7qZUzoXDFTAHTDC4NOoG/ZxU3EvlMPQ==",
+      "dev": true,
+      "engines": {
+        "node": ">=8"
+      }
+    },
+    "node_modules/sinon/node_modules/supports-color": {
+      "version": "7.2.0",
+      "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-7.2.0.tgz",
+      "integrity": "sha512-qpCAvRl9stuOHveKsn7HncJRvv501qIacKzQlO/+Lwxc9+0q2wLyv4Dfvt80/DPn2pqOBsJdDiogXGR9+OvwRw==",
+      "dev": true,
+      "dependencies": {
+        "has-flag": "^4.0.0"
+      },
+      "engines": {
+        "node": ">=8"
+      }
+    },
     "node_modules/slash": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/slash/-/slash-3.0.0.tgz",
@@ -10437,6 +10757,15 @@
         }
       }
     },
+    "@esm-bundle/chai": {
+      "version": "4.3.4",
+      "resolved": "https://registry.npmjs.org/@esm-bundle/chai/-/chai-4.3.4.tgz",
+      "integrity": "sha512-6Tx35wWiNw7X0nLY9RMx8v3EL8SacCFW+eEZOE9Hc+XxmU5HFE2AFEg+GehUZpiyDGwVvPH75ckGlqC7coIPnA==",
+      "dev": true,
+      "requires": {
+        "@types/chai": "^4.2.12"
+      }
+    },
     "@github/prettier-config": {
       "version": "0.0.4",
       "resolved": "https://registry.npmjs.org/@github/prettier-config/-/prettier-config-0.0.4.tgz",
@@ -10517,6 +10846,12 @@
         "tree-kill": "^1.2.1"
       }
     },
+    "@lit/reactive-element": {
+      "version": "1.3.1",
+      "resolved": "https://registry.npmjs.org/@lit/reactive-element/-/reactive-element-1.3.1.tgz",
+      "integrity": "sha512-nOJARIr3pReqK3hfFCSW2Zg/kFcFsSAlIE7z4a0C9D2dPrgD/YSn3ZP2ET/rxKB65SXyG7jJbkynBRm+tGlacw==",
+      "dev": true
+    },
     "@nodelib/fs.scandir": {
       "version": "2.1.5",
       "resolved": "https://registry.npmjs.org/@nodelib/fs.scandir/-/fs.scandir-2.1.5.tgz",
@@ -10543,6 +10878,96 @@
         "fastq": "^1.6.0"
       }
     },
+    "@open-wc/chai-dom-equals": {
+      "version": "0.12.36",
+      "resolved": "https://registry.npmjs.org/@open-wc/chai-dom-equals/-/chai-dom-equals-0.12.36.tgz",
+      "integrity": "sha512-Gt1fa37h4rtWPQGETSU4n1L678NmMi9KwHM1sH+JCGcz45rs8DBPx7MUVeGZ+HxRlbEI5t9LU2RGGv6xT2OlyA==",
+      "dev": true,
+      "requires": {
+        "@open-wc/semantic-dom-diff": "^0.13.16",
+        "@types/chai": "^4.1.7"
+      },
+      "dependencies": {
+        "@open-wc/semantic-dom-diff": {
+          "version": "0.13.21",
+          "resolved": "https://registry.npmjs.org/@open-wc/semantic-dom-diff/-/semantic-dom-diff-0.13.21.tgz",
+          "integrity": "sha512-BONpjHcGX2zFa9mfnwBCLEmlDsOHzT+j6Qt1yfK3MzFXFtAykfzFjAgaxPetu0YbBlCfXuMlfxI4vlRGCGMvFg==",
+          "dev": true
+        }
+      }
+    },
+    "@open-wc/dedupe-mixin": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/@open-wc/dedupe-mixin/-/dedupe-mixin-1.3.0.tgz",
+      "integrity": "sha512-UfdK1MPnR6T7f3svzzYBfu3qBkkZ/KsPhcpc3JYhsUY4hbpwNF9wEQtD4Z+/mRqMTJrKg++YSxIxE0FBhY3RIw==",
+      "dev": true
+    },
+    "@open-wc/scoped-elements": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/@open-wc/scoped-elements/-/scoped-elements-2.0.1.tgz",
+      "integrity": "sha512-JS6ozxUFwFX3+Er91v9yQzNIaFn7OnE0iESKTbFvkkKdNwvAPtp1fpckBKIvWk8Ae9ZcoI9DYZuT2DDbMPcadA==",
+      "dev": true,
+      "requires": {
+        "@lit/reactive-element": "^1.0.0",
+        "@open-wc/dedupe-mixin": "^1.3.0",
+        "@webcomponents/scoped-custom-element-registry": "^0.0.3"
+      }
+    },
+    "@open-wc/semantic-dom-diff": {
+      "version": "0.19.5",
+      "resolved": "https://registry.npmjs.org/@open-wc/semantic-dom-diff/-/semantic-dom-diff-0.19.5.tgz",
+      "integrity": "sha512-Wi0Fuj3dzqlWClU0y+J4k/nqTcH0uwgOWxZXPyeyG3DdvuyyjgiT4L4I/s6iVShWQvvEsyXnj7yVvixAo3CZvg==",
+      "dev": true,
+      "requires": {
+        "@types/chai": "^4.2.11",
+        "@web/test-runner-commands": "^0.5.7"
+      },
+      "dependencies": {
+        "@web/test-runner-commands": {
+          "version": "0.5.13",
+          "resolved": "https://registry.npmjs.org/@web/test-runner-commands/-/test-runner-commands-0.5.13.tgz",
+          "integrity": "sha512-FXnpUU89ALbRlh9mgBd7CbSn5uzNtr8gvnQZPOvGLDAJ7twGvZdUJEAisPygYx2BLPSFl3/Mre8pH8zshJb8UQ==",
+          "dev": true,
+          "requires": {
+            "@web/test-runner-core": "^0.10.20",
+            "mkdirp": "^1.0.4"
+          }
+        },
+        "mkdirp": {
+          "version": "1.0.4",
+          "resolved": "https://registry.npmjs.org/mkdirp/-/mkdirp-1.0.4.tgz",
+          "integrity": "sha512-vVqVZQyf3WLx2Shd0qJ9xuvqgAyKPLAiqITEtqW0oIUjzo3PePDd6fW9iFz30ef7Ysp/oiWqbhszeGWW2T6Gzw==",
+          "dev": true
+        }
+      }
+    },
+    "@open-wc/testing": {
+      "version": "3.1.2",
+      "resolved": "https://registry.npmjs.org/@open-wc/testing/-/testing-3.1.2.tgz",
+      "integrity": "sha512-2KjEszLItrIEZwCLFjWOSy4rnLzLOpgckrKfZjNA39PpFR3xD9bqYU30TTnLRHBk2B/0ZUbHglyca3iwcF964w==",
+      "dev": true,
+      "requires": {
+        "@esm-bundle/chai": "^4.3.4",
+        "@open-wc/chai-dom-equals": "^0.12.36",
+        "@open-wc/semantic-dom-diff": "^0.19.5",
+        "@open-wc/testing-helpers": "^2.1.2",
+        "@types/chai": "^4.2.11",
+        "@types/chai-dom": "^0.0.9",
+        "@types/sinon-chai": "^3.2.3",
+        "chai-a11y-axe": "^1.3.2"
+      }
+    },
+    "@open-wc/testing-helpers": {
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/@open-wc/testing-helpers/-/testing-helpers-2.1.2.tgz",
+      "integrity": "sha512-NEdsV47DnOWaw3Wpp85p4qZ6bdubtGPdlTiblk8vSf2HJ2sR4b3ckyRWzsj/k+pcxrDGt8z0Awz71p+048Rrfg==",
+      "dev": true,
+      "requires": {
+        "@open-wc/scoped-elements": "^2.0.1",
+        "lit": "^2.0.0",
+        "lit-html": "^2.0.0"
+      }
+    },
     "@rollup/plugin-node-resolve": {
       "version": "11.2.1",
       "resolved": "https://registry.npmjs.org/@rollup/plugin-node-resolve/-/plugin-node-resolve-11.2.1.tgz",
@@ -10574,6 +10999,41 @@
       "integrity": "sha512-9NET910DNaIPngYnLLPeg+Ogzqsi9uM4mSboU5y6p8S5DzMTVEsJZrawi+BoDNUVBa2DhJqQYUFvMDfgU062LQ==",
       "dev": true
     },
+    "@sinonjs/commons": {
+      "version": "1.8.3",
+      "resolved": "https://registry.npmjs.org/@sinonjs/commons/-/commons-1.8.3.tgz",
+      "integrity": "sha512-xkNcLAn/wZaX14RPlwizcKicDk9G3F8m2nU3L7Ukm5zBgTwiT0wsoFAHx9Jq56fJA1z/7uKGtCRu16sOUCLIHQ==",
+      "dev": true,
+      "requires": {
+        "type-detect": "4.0.8"
+      }
+    },
+    "@sinonjs/fake-timers": {
+      "version": "9.1.1",
+      "resolved": "https://registry.npmjs.org/@sinonjs/fake-timers/-/fake-timers-9.1.1.tgz",
+      "integrity": "sha512-Wp5vwlZ0lOqpSYGKqr53INws9HLkt6JDc/pDZcPf7bchQnrXJMXPns8CXx0hFikMSGSWfvtvvpb2gtMVfkWagA==",
+      "dev": true,
+      "requires": {
+        "@sinonjs/commons": "^1.7.0"
+      }
+    },
+    "@sinonjs/samsam": {
+      "version": "6.1.1",
+      "resolved": "https://registry.npmjs.org/@sinonjs/samsam/-/samsam-6.1.1.tgz",
+      "integrity": "sha512-cZ7rKJTLiE7u7Wi/v9Hc2fs3Ucc3jrWeMgPHbbTCeVAB2S0wOBbYlkJVeNSL04i7fdhT8wIbDq1zhC/PXTD2SA==",
+      "dev": true,
+      "requires": {
+        "@sinonjs/commons": "^1.6.0",
+        "lodash.get": "^4.4.2",
+        "type-detect": "^4.0.8"
+      }
+    },
+    "@sinonjs/text-encoding": {
+      "version": "0.7.1",
+      "resolved": "https://registry.npmjs.org/@sinonjs/text-encoding/-/text-encoding-0.7.1.tgz",
+      "integrity": "sha512-+iTbntw2IZPb/anVDbypzfQa+ay64MW0Zo8aJ8gZPWMMK6/OubMVb6lUPMagqjOPnmtauXnFCACVl3O7ogjeqQ==",
+      "dev": true
+    },
     "@socket.io/base64-arraybuffer": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/@socket.io/base64-arraybuffer/-/base64-arraybuffer-1.0.2.tgz",
@@ -10626,6 +11086,21 @@
         "@types/responselike": "*"
       }
     },
+    "@types/chai": {
+      "version": "4.3.0",
+      "resolved": "https://registry.npmjs.org/@types/chai/-/chai-4.3.0.tgz",
+      "integrity": "sha512-/ceqdqeRraGolFTcfoXNiqjyQhZzbINDngeoAq9GoHa8PPK1yNzTaxWjA6BFWp5Ua9JpXEMSS4s5i9tS0hOJtw==",
+      "dev": true
+    },
+    "@types/chai-dom": {
+      "version": "0.0.9",
+      "resolved": "https://registry.npmjs.org/@types/chai-dom/-/chai-dom-0.0.9.tgz",
+      "integrity": "sha512-jj4F2NJog2/GBYsyJ8+NvhnWUBbPY4MUAKLdPJE6+568rw12GGXvj0ycUuP5nndVrnJgozmJAoMTvxvjJATXWw==",
+      "dev": true,
+      "requires": {
+        "@types/chai": "*"
+      }
+    },
     "@types/co-body": {
       "version": "6.1.0",
       "resolved": "https://registry.npmjs.org/@types/co-body/-/co-body-6.1.0.tgz",
@@ -10886,6 +11361,37 @@
         "@types/node": "*"
       }
     },
+    "@types/sinon": {
+      "version": "10.0.11",
+      "resolved": "https://registry.npmjs.org/@types/sinon/-/sinon-10.0.11.tgz",
+      "integrity": "sha512-dmZsHlBsKUtBpHriNjlK0ndlvEh8dcb9uV9Afsbt89QIyydpC7NcR+nWlAhASfy3GHnxTl4FX/aKE7XZUt/B4g==",
+      "dev": true,
+      "requires": {
+        "@types/sinonjs__fake-timers": "*"
+      }
+    },
+    "@types/sinon-chai": {
+      "version": "3.2.8",
+      "resolved": "https://registry.npmjs.org/@types/sinon-chai/-/sinon-chai-3.2.8.tgz",
+      "integrity": "sha512-d4ImIQbT/rKMG8+AXpmcan5T2/PNeSjrYhvkwet6z0p8kzYtfgA32xzOBlbU0yqJfq+/0Ml805iFoODO0LP5/g==",
+      "dev": true,
+      "requires": {
+        "@types/chai": "*",
+        "@types/sinon": "*"
+      }
+    },
+    "@types/sinonjs__fake-timers": {
+      "version": "8.1.2",
+      "resolved": "https://registry.npmjs.org/@types/sinonjs__fake-timers/-/sinonjs__fake-timers-8.1.2.tgz",
+      "integrity": "sha512-9GcLXF0/v3t80caGs5p2rRfkB+a8VBGLJZVih6CNFkx8IZ994wiKKLSRs9nuFwk1HevWs/1mnUmkApGrSGsShA==",
+      "dev": true
+    },
+    "@types/trusted-types": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/@types/trusted-types/-/trusted-types-2.0.2.tgz",
+      "integrity": "sha512-F5DIZ36YVLE+PN+Zwws4kJogq47hNgX3Nx6WyDJ3kcplxyke3XIzB8uK5n/Lpm1HBsbGzd6nmGehL8cPekP+Tg==",
+      "dev": true
+    },
     "@types/ws": {
       "version": "7.4.7",
       "resolved": "https://registry.npmjs.org/@types/ws/-/ws-7.4.7.tgz",
@@ -11347,6 +11853,12 @@
         "@web/test-runner-core": "^0.10.20"
       }
     },
+    "@webcomponents/scoped-custom-element-registry": {
+      "version": "0.0.3",
+      "resolved": "https://registry.npmjs.org/@webcomponents/scoped-custom-element-registry/-/scoped-custom-element-registry-0.0.3.tgz",
+      "integrity": "sha512-lpSzgDCGbM99dytb3+J3Suo4+Bk1E13MPnWB42JK8GwxSAxFz+tC7TTv2hhDSIE2IirGNKNKCf3m08ecu6eAsQ==",
+      "dev": true
+    },
     "accepts": {
       "version": "1.3.7",
       "resolved": "https://registry.npmjs.org/accepts/-/accepts-1.3.7.tgz",
@@ -11938,6 +12450,23 @@
         "type-detect": "^4.0.5"
       }
     },
+    "chai-a11y-axe": {
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/chai-a11y-axe/-/chai-a11y-axe-1.4.0.tgz",
+      "integrity": "sha512-m7J6DVAl1ePL2ifPKHmwQyHXdCZ+Qfv+qduh6ScqcDfBnJEzpV1K49TblujM45j1XciZOFeFNqMb2sShXMg/mw==",
+      "dev": true,
+      "requires": {
+        "axe-core": "^4.3.3"
+      },
+      "dependencies": {
+        "axe-core": {
+          "version": "4.4.1",
+          "resolved": "https://registry.npmjs.org/axe-core/-/axe-core-4.4.1.tgz",
+          "integrity": "sha512-gd1kmb21kwNuWr6BQz8fv6GNECPBnUasepcoLbekws23NVBLODdsClRZ+bQ8+9Uomf3Sm3+Vwn0oYG9NvwnJCw==",
+          "dev": true
+        }
+      }
+    },
     "chai-spies": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/chai-spies/-/chai-spies-1.0.0.tgz",
@@ -14817,6 +15346,12 @@
       "integrity": "sha1-0Hf2glVx+CEy+d/67Vh7QCn+/1c=",
       "dev": true
     },
+    "just-extend": {
+      "version": "4.2.1",
+      "resolved": "https://registry.npmjs.org/just-extend/-/just-extend-4.2.1.tgz",
+      "integrity": "sha512-g3UB796vUFIY90VIv/WX3L2c8CS2MdWUww3CNrYmqza1Fg0DURc2K/O4YrnklBdQarSJ/y8JnJYDGc+1iumQjg==",
+      "dev": true
+    },
     "karma": {
       "version": "6.3.16",
       "resolved": "https://registry.npmjs.org/karma/-/karma-6.3.16.tgz",
@@ -15417,6 +15952,36 @@
       "integrity": "sha512-wdv94WUjaqUwtW8DOapng45Yah62c5O5geNVeoSQlnoagfbTO/YbiwNlfzDIF1xNKRkPlsfr/oWHhXsaHXDivg==",
       "dev": true
     },
+    "lit": {
+      "version": "2.2.1",
+      "resolved": "https://registry.npmjs.org/lit/-/lit-2.2.1.tgz",
+      "integrity": "sha512-dSe++R50JqrvNGXmI9OE13de1z5U/Y3J2dTm/9GC86vedI8ILoR8ZGnxfThFpvQ9m0lR0qRnIR4IiKj/jDCfYw==",
+      "dev": true,
+      "requires": {
+        "@lit/reactive-element": "^1.3.0",
+        "lit-element": "^3.2.0",
+        "lit-html": "^2.2.0"
+      }
+    },
+    "lit-element": {
+      "version": "3.2.0",
+      "resolved": "https://registry.npmjs.org/lit-element/-/lit-element-3.2.0.tgz",
+      "integrity": "sha512-HbE7yt2SnUtg5DCrWt028oaU4D5F4k/1cntAFHTkzY8ZIa8N0Wmu92PxSxucsQSOXlODFrICkQ5x/tEshKi13g==",
+      "dev": true,
+      "requires": {
+        "@lit/reactive-element": "^1.3.0",
+        "lit-html": "^2.2.0"
+      }
+    },
+    "lit-html": {
+      "version": "2.2.1",
+      "resolved": "https://registry.npmjs.org/lit-html/-/lit-html-2.2.1.tgz",
+      "integrity": "sha512-AiJ/Rs0awjICs2FioTnHSh+Np5dhYSkyRczKy3wKjp8qjLhr1Ov+GiHrUQNdX8ou1LMuznpIME990AZsa/tR8g==",
+      "dev": true,
+      "requires": {
+        "@types/trusted-types": "^2.0.2"
+      }
+    },
     "locate-path": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/locate-path/-/locate-path-2.0.0.tgz",
@@ -15994,6 +16559,36 @@
       "integrity": "sha512-hZXc7K2e+PgeI1eDBe/10Ard4ekbfrrqG8Ep+8Jmf4JID2bNg7NvCPOZN+kfF574pFQI7mum2AUqDidoKqcTOw==",
       "dev": true
     },
+    "nise": {
+      "version": "5.1.1",
+      "resolved": "https://registry.npmjs.org/nise/-/nise-5.1.1.tgz",
+      "integrity": "sha512-yr5kW2THW1AkxVmCnKEh4nbYkJdB3I7LUkiUgOvEkOp414mc2UMaHMA7pjq1nYowhdoJZGwEKGaQVbxfpWj10A==",
+      "dev": true,
+      "requires": {
+        "@sinonjs/commons": "^1.8.3",
+        "@sinonjs/fake-timers": ">=5",
+        "@sinonjs/text-encoding": "^0.7.1",
+        "just-extend": "^4.0.2",
+        "path-to-regexp": "^1.7.0"
+      },
+      "dependencies": {
+        "isarray": {
+          "version": "0.0.1",
+          "resolved": "https://registry.npmjs.org/isarray/-/isarray-0.0.1.tgz",
+          "integrity": "sha1-ihis/Kmo9Bd+Cav8YDiTmwXR7t8=",
+          "dev": true
+        },
+        "path-to-regexp": {
+          "version": "1.8.0",
+          "resolved": "https://registry.npmjs.org/path-to-regexp/-/path-to-regexp-1.8.0.tgz",
+          "integrity": "sha512-n43JRhlUKUAlibEJhPeir1ncUID16QnEjNpwzNdO3Lm4ywrBpBZ5oLD0I6br9evr1Y9JTqwRtAh7JLoOzAQdVA==",
+          "dev": true,
+          "requires": {
+            "isarray": "0.0.1"
+          }
+        }
+      }
+    },
     "node-fetch": {
       "version": "2.6.7",
       "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.6.7.tgz",
@@ -17098,6 +17693,37 @@
       "integrity": "sha512-VUJ49FC8U1OxwZLxIbTTrDvLnf/6TDgxZcK8wxR8zs13xpx7xbG60ndBlhNrFi2EMuFRoeDoJO7wthSLq42EjA==",
       "dev": true
     },
+    "sinon": {
+      "version": "13.0.1",
+      "resolved": "https://registry.npmjs.org/sinon/-/sinon-13.0.1.tgz",
+      "integrity": "sha512-8yx2wIvkBjIq/MGY1D9h1LMraYW+z1X0mb648KZnKSdvLasvDu7maa0dFaNYdTDczFgbjNw2tOmWdTk9saVfwQ==",
+      "dev": true,
+      "requires": {
+        "@sinonjs/commons": "^1.8.3",
+        "@sinonjs/fake-timers": "^9.0.0",
+        "@sinonjs/samsam": "^6.1.1",
+        "diff": "^5.0.0",
+        "nise": "^5.1.1",
+        "supports-color": "^7.2.0"
+      },
+      "dependencies": {
+        "has-flag": {
+          "version": "4.0.0",
+          "resolved": "https://registry.npmjs.org/has-flag/-/has-flag-4.0.0.tgz",
+          "integrity": "sha512-EykJT/Q1KjTWctppgIAgfSO0tKVuZUjhgMr17kqTumMl6Afv3EISleU7qZUzoXDFTAHTDC4NOoG/ZxU3EvlMPQ==",
+          "dev": true
+        },
+        "supports-color": {
+          "version": "7.2.0",
+          "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-7.2.0.tgz",
+          "integrity": "sha512-qpCAvRl9stuOHveKsn7HncJRvv501qIacKzQlO/+Lwxc9+0q2wLyv4Dfvt80/DPn2pqOBsJdDiogXGR9+OvwRw==",
+          "dev": true,
+          "requires": {
+            "has-flag": "^4.0.0"
+          }
+        }
+      }
+    },
     "slash": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/slash/-/slash-3.0.0.tgz",
diff --git a/package.json b/package.json
index be32a0c..53c28ee 100644
--- a/package.json
+++ b/package.json
@@ -27,14 +27,15 @@
     "build:docs": "cd docs && JEKYLL_ENV=production bundle exec jekyll build",
     "clean": "tsc --build --clean",
     "lint": "eslint . --ignore-path .gitignore",
-    "pretest": "npm run build",
-    "test": "npm run lint && karma start test/karma.config.cjs",
+    "pretest": "npm run build && npm run lint",
+    "test": "web-test-runner test/* --node-resolve",
     "postpublish": "npm publish --ignore-scripts --@github:registry='https://npm.pkg.github.com'"
   },
   "prettier": "@github/prettier-config",
   "devDependencies": {
     "@github/prettier-config": "^0.0.4",
     "@lhci/cli": "^0.7.0",
+    "@open-wc/testing": "^3.1.2",
     "@typescript-eslint/eslint-plugin": "^5.16.0",
     "@typescript-eslint/parser": "^5.16.0",
     "@web/test-runner": "^0.13.27",
@@ -50,6 +51,7 @@
     "karma-mocha": "^2.0.1",
     "karma-mocha-reporter": "^2.2.5",
     "mocha": "^8.3.0",
+    "sinon": "^13.0.1",
     "tslib": "^2.3.1",
     "typescript": "^4.6.3"
   }