Examine source code of Auto Close Duplicate Tabs

{
  "author": "igorlogius",
  "homepage_url": "https://github.com/igorlogius/webextensions/tree/main/auto-close-duplicate-tabs",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_area": "navbar"
  },
  "description": "Auto close duplicate tabs with options to configure what duplicate means and what scope to consider",
  "icons": {
    "128": "icon.png"
  },
  "manifest_version": 2,
  "name": "Auto Close Duplicate Tabs",
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "cookies",
    "storage",
    "tabs",
    "tabGroups"
  ],
  "version": "1.9.30",
  "browser_specific_settings": {
    "gecko": {
      "id": "{83d63d9e-824f-49b4-9c28-468b9fb2f300}"
    }
  }
}