Examine source code of rickroll blocker

{
  "manifest_version": 2,
  "name": "anti rickroll",
  "version": "6.9",
  "description": "blocks the rickroll video on youtube (https://www.youtube.com/watch?v=dQw4w9WgXcQ)",
  "icons": {
    "48": "icons/rick.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/watch?v=dQw4w9WgXcQ"
      ],
      "js": [
        "fix.js"
      ]
    }
  ]
}