Examine source code of Reopen Closed Tabs

{
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  "name": "__MSG_extensionName__",
  "version": "8.0.0",
  "description": "__MSG_extensionDescription__",
  "browser_specific_settings": {
    "gecko": {
      "id": "{4853d046-c5a3-536b-bc38-620fd935ee1d}",
      "strict_min_version": "120.0"
    }
  },
  "icons": {
    "24": "icons/undoclosetab.svg",
    "32": "icons/undoclosetab.svg",
    "50": "icons/undoclosetab.svg"
  },
  "background": {
    "scripts": [
      "utils/iconupdater.js",
      "utils/storage.js",
      "tabhandling.js",
      "background.js"
    ]
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": "icons/undoclosetab.svg",
    "theme_icons": [
      {
        "dark": "icons/undoclosetab.svg",
        "light": "icons/undoclosetab-light.svg",
        "size": 19
      }
    ]
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true,
    "open_in_tab": false
  },
  "commands": {
    "_execute_browser_action": {}
  },
  "permissions": [
    "menus",
    "tabs",
    "sessions",
    "storage",
    "theme"
  ],
  "default_locale": "en"
}