Examine source code of ReContainer

{
  "manifest_version": 2,
  "name": "ReContainer",
  "version": "1.1.1",
  "description": "Automatically open domains in specified containers.",
  "browser_specific_settings": {
    "gecko": {
      "id": "recontainer@extension",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "permissions": [
    "contextualIdentities",
    "cookies",
    "tabs",
    "webRequest",
    "webRequestBlocking",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "ReContainer"
  },
  "icons": {
    "48": "icon48.png",
    "96": "icon96.png"
  }
}