Examine source code of Tab Group Saver

{
  "manifest_version": 2,
  "name": "Tab Group Saver",
  "version": "1.2",
  "description": "Saves and restores Firefox tab groups when they are accidentally closed.",
  "permissions": [
    "tabs",
    "tabGroups",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Tab Group Saver",
    "default_icon": "icons/icon.svg"
  },
  "icons": {
    "48": "icons/icon.svg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "tab-group-saver@aaronbutler",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}