Examine source code of Proxy-ad-dumper

{
  "manifest_version": 2,
  "name": "Proxy-ad-dumper",
  "description": "This addon is based on Mozilla's Proxy-Blocker example, but it has been modified in order to proxy adverts to an unexisting location, thus blocking stealthily unwanted ads. This addon is not recomended for any end users who do not understand how does it work, as it is not exactly stable or done 'accordingly to the books'.",
  "version": "3.0",
  "icons": {
    "48": "icons/block.svg",
    "96": "icons/block.svg"
  },
  "applications": {
    "gecko": {
      "strict_min_version": "56.0a1"
    }
  },
  "background": {
    "scripts": [
      "background/proxy-handler.js"
    ]
  },
  "options_ui": {
    "page": "options/options.html",
    "browser_style": true
  },
  "permissions": [
    "proxy",
    "storage",
    "<all_urls>"
  ]
}