Examine source code of Block Topics

{
  "manifest_version": 2,
  "name": "Block Topics",
  "version": "1.0",
  "description": "Remove recommended topic in twitter home.",
  "content_scripts": [
    {
      "matches": [
        "https://twitter.com/home"
      ],
      "js": [
        "block.js"
      ]
    }
  ]
}