Examine source code of Network Request Blocker

{
  "manifest_version": 2,
  "name": "Network Request 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": "Request Blocker",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ecd14094-f9bc-4c93-9558-e7d37066e08f}",
      "strict_min_version": "90.0"
    }
  }
}