How to use the amqp._AMQPWriter function in amqp

def start(self, args):
        version_major = args.read_octet()
        version_minor = args.read_octet()
        properties = args.read_table()
        mechanisms = args.read_longstr().split(' ')
        locales = args.read_longstr().split(' ')
        print 'Start from server, version: %d.%d, properties: %s, mechanisms: %s, locales: %s' % (version_major, version_minor, str(properties), mechanisms, locales)

        login = _AMQPWriter()
        login.write_table({"LOGIN": "guest", "PASSWORD": "guest"})
        login = login.getvalue()[4:]    #Skip the length at the beginning

        self.start_ok({'product': 'Python AMQP', 'version': '0.1'}, 'AMQPLAIN', login, 'en_US')

def open(self, virtual_host, capabilities='', insist=False):
        args = _AMQPWriter()
        args.write_shortstr(virtual_host)
        args.write_shortstr(capabilities)
        args.write_octet(1 if insist else 0)
        self.send_method_frame(0, 10, 40, args.getvalue())

def send_method_frame(self, channel, class_id, method_id, packed_args):
        pkt = _AMQPWriter()

        pkt.write_octet(1)
        pkt.write_short(channel)
        pkt.write_long(len(packed_args)+4)  # 4 = length of class_id and method_id in payload

        pkt.write_short(class_id)
        pkt.write_short(method_id)
        pkt.write(packed_args)

        pkt.write_octet(0xce)
        pkt = pkt.getvalue()
#        hexdump(pkt)
        self.out.write(pkt)
        self.out.flush()

def tune_ok(self, channel_max, frame_max, heartbeat):
        args = _AMQPWriter()
        args.write_short(channel_max)
        args.write_long(frame_max)
        args.write_short(heartbeat)
        self.send_method_frame(0, 10, 31, args.getvalue())
        self.open('/')

def serialize(self):
        args = _AMQPWriter()
        args.write_short(0)
        packed_properties = args.getvalue()
        return packed_properties, self.body

def write_table(self, d):
        self.flushbits()
        table_data = _AMQPWriter()
        for k, v in d.items():
            table_data.write_shortstr(k)
            if isinstance(v, basestring):
                if isinstance(v, unicode):
                    v = v.encode('utf-8')
                table_data.write('S')
                table_data.write_longstr(v)
            elif isinstance(v, [int, long]):
                table_data.write('I')
                table_data.write(pack('>i', v))
            elif isinstance(v, decimal):
                table_data.write('D')
                table_data.write_octet(4)
                table_data.write_long(int(v * 10))
            elif isinstance(v, datetime):
                table_data.write('T')