How to use the nfstream.ndpi_bindings.NDPIIdStruct function in nfstream

def on_flow_init(self, flow):
        NFStreamClassifier.on_flow_init(self, flow)
        flow.classifiers[self.name]['ndpi_flow'] = NDPIFlowStruct()
        memset(byref(flow.classifiers[self.name]['ndpi_flow']), 0, sizeof(NDPIFlowStruct))
        flow.classifiers[self.name]['detected_protocol'] = NDPIProtocol()
        flow.classifiers[self.name]['detection_completed'] = 0
        flow.classifiers[self.name]['src_id'] = pointer(NDPIIdStruct())
        flow.classifiers[self.name]['dst_id'] = pointer(NDPIIdStruct())
        flow.classifiers[self.name]['application_name'] = ''
        flow.classifiers[self.name]['category_name'] = ''
        flow.classifiers[self.name]['guessed'] = 0

('pplive_stage2', c_uint8, 2),
    ('pplive_stage3', c_uint8, 2),
    ('starcraft_udp_stage', c_uint8, 3),
    ('ovpn_session_id', c_uint8 * 8),
    ('ovpn_counter', c_uint8),
    ('tinc_state', c_uint8),
    ('TincCacheEntry', TincCacheEntry),
    ('csgo_strid', c_uint8 * 18),
    ('csgo_state', c_uint8),
    ('csgo_s2', c_uint8),
    ('csgo_id2', c_uint32),
    ('kxun_counter', c_uint16),
    ('iqiyi_counter', c_uint16),
    ('packet', NDPIPacketStruct),
    ('flow', POINTER(NDPIFlowStruct)),
    ('src', POINTER(NDPIIdStruct)),
    ('dst', POINTER(NDPIIdStruct))
]

# ----------------------------------------------- nDPI APIs ------------------------------------------------------------

""" ndpi_detection_giveup: Function to be called before we give up with detection for a given flow.
                           This function reduces the NDPI_UNKNOWN_PROTOCOL detection. """
ndpi.ndpi_detection_giveup.restype = NDPIProtocol
ndpi.ndpi_detection_giveup.argtypes = [POINTER(NDPIDetectionModuleStruct),
                                      POINTER(NDPIFlowStruct), c_uint8,
                                      POINTER(c_uint8)]

""" ndpi_detection_process_packet: Processes one packet and returns the ID of the detected protocol.
                                   This is the MAIN PACKET PROCESSING FUNCTION. """
ndpi.ndpi_detection_process_packet.restype = NDPIProtocol
ndpi.ndpi_detection_process_packet.argtypes = [POINTER(NDPIDetectionModuleStruct),