How to use the pypsexec.rpc.BindNakPDU function in pypsexec

def test_parse_pdu_known():
    message = BindNakPDU()
    message['packed_drep'] = DataRepresentationFormat()
    message['call_id'] = 4
    message['provider_reject_reason'] = BindNakReason.LOCAL_LIMIT_EXCEEDED
    message['p_protocols'] = [5]
    data = message.pack()
    actual = parse_pdu(data)
    assert isinstance(actual, BindNakPDU)
    assert len(actual) == 21

def test_parse_message(self):
        actual = BindNakPDU()
        data = b"\x05" \
               b"\x00" \
               b"\x0d" \
               b"\x00" \
               b"\x10\x00\x00\x00" \
               b"\x15\x00" \
               b"\x00\x00" \
               b"\x04\x00\x00\x00" \
               b"\x02\x00" \
               b"\x01" \
               b"\x05\x00"
        data = actual.unpack(data)
        assert len(actual) == 21
        assert actual['rpc_vers'].get_value() == 5
        assert actual['rpc_vers_minor'].get_value() == 0
        assert actual['ptype'].get_value() == PType.BIND_NAK

def test_create_message(self):
        message = BindNakPDU()
        message['packed_drep'] = DataRepresentationFormat()
        message['call_id'] = 4
        message['provider_reject_reason'] = BindNakReason.LOCAL_LIMIT_EXCEEDED
        message['p_protocols'] = [5]
        expected = b"\x05" \
                   b"\x00" \
                   b"\x0d" \
                   b"\x00" \
                   b"\x10\x00\x00\x00" \
                   b"\x15\x00" \
                   b"\x00\x00" \
                   b"\x04\x00\x00\x00" \
                   b"\x02\x00" \
                   b"\x01" \
                   b"\x05\x00"
        actual = message.pack()

def test_parse_pdu_known():
    message = BindNakPDU()
    message['packed_drep'] = DataRepresentationFormat()
    message['call_id'] = 4
    message['provider_reject_reason'] = BindNakReason.LOCAL_LIMIT_EXCEEDED
    message['p_protocols'] = [5]
    data = message.pack()
    actual = parse_pdu(data)
    assert isinstance(actual, BindNakPDU)
    assert len(actual) == 21

def parse_pdu(data):
    """
    Converts the raw byte string of PDU data into a *PDU() structure. If the
    type is invalid or unknown to pypsexec it will throw a PDUException.

    :param data: The byte string returned in the buffer of the IOCTL response
    :return: *PDU() structure that is dependent on the type being parsed
    """
    type = struct.unpack("

('call_id', IntField(size=4)),
            ('provider_reject_reason', EnumField(
                size=2,
                enum_type=BindNakReason
            )),
            # versions
            ('n_protocols', IntField(
                size=1,
                default=lambda s: len(s['p_protocols'].get_value())
            )),
            ('p_protocols', ListField(
                list_type=IntField(size=2),
                list_count=lambda s: s['n_protocols'].get_value()
            ))
        ])
        super(BindNakPDU, self).__init__()