Examine source code of Private Window Blocker

{
  "manifest_version": 2,
  "name": "Private Window Blocker",
  "version": "1.0",
  "description": "Automatically closes private windows.",
  "permissions": [
    "tabs",
    "windows"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ad8f5b53-80d7-427e-b38b-98726eb6102e}"
    }
  }
}