@classmethod
def drop_all(cls, client):
    """Drop all tables derived from this base class

        Before you call this, import all modules that define the models that you want to drop
        tables for (this registers your models with the base class metadata object).

        Args:
            client (ozelot.client.Client): database client to use
        """
    cls.metadata.drop_all(bind=client.get_engine())
