List permissions for a Pack

{
    "items": [
        {
            "principal": {
                "email": "string",
                "type": "user"
            },
            "access": "view",
            "id": "string"
        }
    ],
    "permissionUsers": [
        {
            "name": "John Doe",
            "loginId": "user@example.com",
            "pictureLink": "https://cdn.coda.io/avatars/default_avatar.png",
            "type": "user"
        }
    ]
}