':param args: column types representing tuple composition'

def __init__(self, *args, **kwargs):

    if (not args):
        raise ValueError('Tuple    must    specify    at    least    one    inner    type')
    super(Tuple, self).__init__(args, **kwargs)
    self.db_type = 'tuple<{0}>'.format(',    '.join((typ.db_type for typ in self.types)))
