Examine source code of Clear Active Tabs

{
  "manifest_version": 2,
  "name": "Clear Active Tabs",
  "version": "1.9",
  "description": "Closes non-pinned tabs with smart focus management",
  "icons": {
    "32": "icons/x.svg",
    "48": "icons/x.svg",
    "96": "icons/x.svg"
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_action": {
    "default_title": "Clear Active Tabs",
    "default_icon": "icons/x.svg"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+X"
      },
      "description": "Clear non-pinned tabs"
    }
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "web_accessible_resources": [
    "icons/x.svg",
    "icons/check.svg"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{41b4a885-3e48-4d23-b2a5-0a2395ed8cff}"
    }
  }
}