'Receive bytes data as a bytes object.'

def recv_bytes(self, maxlength=None):

    self._check_closed()
    self._check_readable()
    if ((maxlength is not None) and (maxlength < 0)):
        raise ValueError('negative    maxlength')
    buf = self._recv_bytes(maxlength)
    if (buf is None):
        self._bad_message_length()
    return buf.getvalue()
