Examine source code of Proxy by Magus

{
  "manifest_version": 2,
  "name": "Proxy by Magus",
  "version": "2.3",
  "description": "Гибкий прокси-менеджер с per-tab режимом",
  "permissions": [
    "proxy",
    "storage",
    "<all_urls>",
    "tabs",
    "webRequest",
    "webRequestBlocking"
  ],
  "background": {
    "scripts": [
      "common.js",
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "48": "icon-proxy-off.png"
    },
    "default_title": "Proxy",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "proxy-by-sites@example.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}