Examine source code of Container Reuse

{
  "manifest_version": 2,
  "name": "Container Reuse",
  "version": "1.0",
  "description": "Open new tab in the current container",
  "icons": {
    "48": "icons/icon-48.png"
  },
  "permissions": [
    "contextualIdentities",
    "cookies"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false,
    "type": "module"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9d8e0c04-b8f4-4e15-885f-8e78df229151}"
    }
  }
}