Private method to send packed message and receive the reply message.
        :param packed_message: a binary string containing the entire message payload

def __send_message_recv_reply(self, packed_message):
        """
        Private method to send packed message and receive the reply message.
        :param packed_message: a binary string containing the entire message payload
        """
        payload = io.BytesIO()
        try:
            with self._socket_lock:
                self._socket.sendall(packed_message)

                # Read first message header
                raw_header = self._socket.recv(32)
                header = ReplyMessage.header_from_raw_header_data(raw_header)

                # from pyhdb.lib.stringlib import allhexlify
                # print 'Raw msg header:', allhexlify(raw_header)
                msg = 'Message header (32 bytes): sessionid: %d, packetcount: %d, length: %d, size: %d, noofsegm: %d'
                debug(msg, *(header[:5]))

                # Receive complete message payload
                while payload.tell() < header.payload_length:
                    _payload = self._socket.recv(header.payload_length - payload.tell())
                    if not _payload:
                        break   # jump out without any warning??
                    payload.write(_payload)

                debug('Read %d bytes payload from socket', payload.tell())

                # Keep session id of connection up to date
                if self.session_id != header.session_id:
                    self.session_id = header.session_id
                    self.packet_count = -1
        except socket.timeout:
            raise ConnectionTimedOutError()
        except (IOError, OSError) as error:
            raise OperationalError("Lost connection to HANA server (%r)" % error)

        payload.seek(0)  # set pointer position to beginning of buffer
        return ReplyMessage.unpack_reply(header, payload)