Examine source code of Bulk Container Switcher

{
  "manifest_version": 2,
  "name": "Bulk Container Switcher",
  "version": "1.0.1",
  "description": "Quickly switch multiple selected tabs to any Firefox container at once. Perfect for organizing your browsing with Multi-Account Containers.",
  "icons": {
    "48": "icon.svg",
    "96": "icon.svg"
  },
  "permissions": [
    "tabs",
    "contextualIdentities",
    "cookies",
    "notifications"
  ],
  "browser_action": {
    "default_icon": "icon.svg",
    "default_popup": "popup.html",
    "default_title": "Switch to Container"
  },
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{8019c5ef-5de8-4106-8205-451b5bf1a1fe}"
    }
  }
}