Examine source code of Cycle Live Tabs

{
  "manifest_version": 2,
  "name": "Cycle Live Tabs",
  "version": "1.0",
  "description": "Cycle only through loaded (non-discarded) tabs, skipping unloaded ones.",
  "permissions": [
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "cycle-live-tabs@nasreddin",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "commands": {
    "cycle-tab-next": {
      "suggested_key": {
        "default": "Alt+Down"
      },
      "description": "Switch to next loaded tab"
    },
    "cycle-tab-previous": {
      "suggested_key": {
        "default": "Alt+Up"
      },
      "description": "Switch to previous loaded tab"
    }
  }
}