Examine source code of Container Launcher

{
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "container-launcher@afnankhan",
      "strict_min_version": "61.0"
    }
  },
  "name": "Container Launcher",
  "version": "2019.2.16resigned1",
  "icons": {
    "128": "images/icon.png"
  },
  "browser_action": {
    "default_title": "Container Launcher",
    "default_icon": "images/icon.png",
    "default_popup": "html/popup.html",
    "default_area": "tabstrip",
    "browser_style": true
  },
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "permissions": [
    "contextualIdentities",
    "menus",
    "bookmarks",
    "cookies"
  ]
}