Examine source code of Tab Limiter

{
  "manifest_version": 2,
  "name": "Container Tab Limiter",
  "version": "1.0.2",
  "description": "Limit number of open tabs per Firefox container (contextual identity). Auto-close oldest or newest tabs when the limit is exceeded.",
  "permissions": [
    "tabs",
    "storage",
    "contextualIdentities"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Container Tab Limiter",
    "default_popup": "popup.html"
  },
  "icons": {
    "48": "icons/icon48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8665eabb-51b1-4c58-b5e3-9219534eb28b}"
    }
  }
}