Examine source code of nolikes

{
  "manifest_version": 2,
  "name": "nolikes",
  "author": "Daniel Hofstetter (@dhofstet)",
  "version": "1.1resigned1",
  "description": "Hides liked tweets in your Twitter timeline",
  "icons": {
    "48": "icons/nolikes.svg"
  },
  "content_scripts": [
    {
      "matches": [
        "https://twitter.com/*"
      ],
      "css": [
        "nolikes.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{19c70147-25f4-473a-b74b-3cdd9fe4eead}"
    }
  }
}