Examine source code of 2dehaas

{
  "manifest_version": 2,
  "name": "2dehaas - 1.3.3",
  "version": "1.3.3",
  "browser_specific_settings": {
    "gecko": {
      "id": "2dehaas@2dehaas.nonexisting",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "description": "Enhanced features for 2dehands.be and 2ememain.be",
  "icons": {
    "48": "icons/logo_48.png",
    "96": "icons/logo_96.png"
  },
  "browser_action": {
    "default_icon": "icons/logo_32.png",
    "default_title": "2dehaas",
    "default_popup": "popup/settings.html"
  },
  "options_ui": {
    "page": "popup/settings.html"
  },
  "permissions": [
    "storage",
    "menus",
    "webRequest",
    "webRequestBlocking",
    "https://*.2dehands.be/*",
    "https://*.2dehands.com/*",
    "https://*.2ememain.be/*",
    "https://*.icas.io/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.2dehands.be/v/*",
        "https://www.2ememain.be/v/*"
      ],
      "js": [
        "libs/css.js",
        "libs/get_elem.js",
        "ad_page.js",
        "libs/helpers.js",
        "libs/download.js"
      ]
    },
    {
      "matches": [
        "https://www.2dehands.be/q/*",
        "https://www.2dehands.be/l/*",
        "https://www.2ememain.be/q/*",
        "https://www.2ememain.be/l/*"
      ],
      "js": [
        "libs/css.js",
        "libs/get_elem.js",
        "ad_list.js",
        "libs/helpers.js"
      ]
    },
    {
      "matches": [
        "https://www.2dehands.be/notifications*",
        "https://www.2ememain.be/notifications*"
      ],
      "js": [
        "libs/css.js",
        "libs/get_elem.js",
        "notifications.js",
        "libs/helpers.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js",
      "url_rewrite.js",
      "background_blockusers.js"
    ]
  }
}