Examine source code of Close and Forget This Tab

{
  "name": "Close and Forget This Tab",
  "description": "Close the current tab, and remove it from the browsing history. Use keyboard command Alt + w.",
  "permissions": [
    "activeTab",
    "menus",
    "history"
  ],
  "version": "0.1.1",
  "icons": {
    "48": "static/icon-48.png",
    "128": "static/icon-128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "static/icon-128.png",
    "default_title": "Close and Forget This Tab"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Alt+W"
      }
    }
  },
  "manifest_version": 2,
  "homepage_url": "https://browsernative.com/close-and-forget-this-tab/"
}