Examine source code of Lean Tab Limiter

{
  "applications": {
    "gecko": {
      "id": "lean-tab-limiter@etienneguerlain.fr",
      "strict_min_version": "58.0a1"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options/options.html",
    "browser_style": true
  },
  "description": "Limits the number of tabs that can be opened",
  "manifest_version": 2,
  "name": "Lean Tab Limiter",
  "author": "Etienne Guerlain",
  "homepage_url": "https://github.com/eguerlain/lean-tab-limiter",
  "icons": {
    "48": "icons/lean-tab-limiter-48.png"
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "version": "0.2resigned1",
  "DEFAULT_TAB_LIMIT": 6
}