Examine source code of Tab Limiterzv

{
  "manifest_version": 2,
  "name": "Tab Limiter",
  "version": "1.0",
  "description": "Limit the number of open tabs in Firefox.",
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "Tab Limiter"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d6ffccea-6985-4b77-a160-db589593c968}"
    }
  }
}