Examine source code of Containers 18+

{
  "manifest_version": 2,
  "name": "Containers 18+",
  "version": "0.0.5",
  "description": "Containers 18+ isolates your NSFW activity from the rest of your web activity.",
  "permissions": [
    "<all_urls>",
    "contextualIdentities",
    "cookies",
    "management",
    "tabs",
    "webRequestBlocking",
    "webRequest",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{fe34f215-534c-4d1c-b3ec-3c199d0904c5}"
    }
  }
}