gecko-dev/browser/components/syncedtabs/test/xpcshell/head.js

var { XPCOMUtils } = ChromeUtils.importESModule(
  "resource://gre/modules/XPCOMUtils.sys.mjs"
);
var { sinon } = ChromeUtils.importESModule(
  "resource://testing-common/Sinon.sys.mjs"
);

do_get_profile(); // fxa needs a profile directory for storage.