Examine source code of Limit Tabs

{
  "applications": {
    "gecko": {
      "id": "rudolf.fernandes@gmail.com",
      "strict_min_version": "79.0a1"
    }
  },
  "description": "Limits tabs to maintain system responsiveness",
  "manifest_version": 2,
  "name": "Limit Tabs",
  "version": "2.2.10",
  "background": {
    "scripts": [
      "limittabsto2.js"
    ]
  },
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_icon": {
      "32": "icons/enabled.png"
    }
  }
}