Examine source code of Exclusive Containers

{
  "manifest_version": 2,
  "name": "Exclusive Containers",
  "version": "0.1.1",
  "description": "Ensure exclusivity of containers with designated domains by opening other domains in a default container.",
  "permissions": [
    "<all_urls>",
    "webRequest",
    "webRequestBlocking",
    "cookies",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}