Examine source code of NetRequest Blocker

{
  "manifest_version": 2,
  "name": "NetRequest Blocker",
  "description": "Block network requests (XHR, Fetch, images, etc.) by user-defined URL patterns",
  "version": "1.0",
  "icons": {
    "64": "icons/icon-64.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": "icons/icon-64.png",
    "default_title": "NetRequest Blocker",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{401b40d6-53a7-4840-8ece-fc6ccbb3d91c}",
      "strict_min_version": "100.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}