Examine source code of Container Interceptor

{
  "manifest_version": 2,
  "name": "Container Interceptor",
  "version": "2.2",
  "description": "Intercepts navigation to let user choose a container.",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "contextualIdentities",
    "cookies",
    "storage",
    "menus",
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "web_accessible_resources": [
    "interstitial.html",
    "interstitial.js",
    "style.css"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "container-interceptor@antigravity.local",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "browser_action": {
    "default_title": "Container Interceptor",
    "default_popup": "popup.html",
    "default_icon": "icon-48.png"
  },
  "icons": {
    "48": "icon-48.png",
    "96": "icon-96.png"
  }
}