@classmethod
def _to_list(cls, data):
    """Transform resource data to list.

        A client can send resource or collection in HTTP request. This method
        always converts the top level ``data`` object to a list of resources.

        Args:
            data (dict): Top level JSON ``data`` property.

        Returns:
            tuple: List of attributes
        """
    if not isinstance(data, (list, tuple)):
        return data,
    return tuple(data)
