@classmethod
def __class_attribute(cls, data, attribute, cl, *args, **kwargs):
    """Return the attribute from the JSON data and instantiate the class.

        "param dict data: dictionary used to put together the model or None
        "param str attribute: key of the attribute
        :param class cl: class that will be instantiated
        :returns: instantiated class or None
        :rtype: object or None
        """
    value = cls._get_attribute(data, attribute)
    if value:
        return cl(value, *args, **kwargs)
    return value
