def METHOD_NAME(self):
    """
    Default query method implemented in the
    metaclass Query().
    """
    location_columns = ",".join(self.ul.spatial_unit.location_id_columns)
    sql = f"""
    SELECT 
        subscriber, 
        COUNT(*) as value  
        FROM
    ({self.ul.get_query()}) AS _
    GROUP BY subscriber  
    """
    return sql