Examine source code of Filter Lists Blocker

{
  "manifest_version": 2,
  "name": "Filter Lists Blocker",
  "description": "Uses the proxy API to block requests to specific hosts in pre-defined filter lists.",
  "version": "0.1",
  "icons": {
    "48": "icons/block.svg",
    "96": "icons/block.svg"
  },
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "60.0"
    }
  },
  "background": {
    "scripts": [
      "background/filter_lists_blocker.js"
    ]
  },
  "web_accessible_resources": [
    "data/blockhosts.txt"
  ],
  "permissions": [
    "proxy",
    "storage",
    "<all_urls>"
  ]
}