Examine source code of List Domain Blocker

{
  "manifest_version": 2,
  "name": "Domain Blocker",
  "description": "Uses the proxy API to block requests to specific websites.",
  "version": "2.0",
  "icons": {
    "32": "icons/logo_32.png",
    "64": "icons/logo_64.png",
    "128": "icons/logo_128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "56.0a1"
    }
  },
  "background": {
    "scripts": [
      "background/proxy-handler.js"
    ]
  },
  "options_ui": {
    "page": "options/options.html",
    "browser_style": false
  },
  "permissions": [
    "proxy",
    "storage",
    "<all_urls>"
  ]
}