uint16_t MqttConnection::Unsubscribe()

in source/mqtt/MqttClient.cpp [619:646]
23 lines of code
4 McCabe index (conditional complexity)

            uint16_t MqttConnection::Unsubscribe(
                const char *topicFilter,
                OnOperationCompleteHandler &&onOpComplete) noexcept
            {
                auto opCompleteCallbackData = Crt::New<OpCompleteCallbackData>(m_owningClient->allocator);

                if (!opCompleteCallbackData)
                {
                    return 0;
                }

                opCompleteCallbackData->connection = this;
                opCompleteCallbackData->allocator = m_owningClient->allocator;
                opCompleteCallbackData->onOperationComplete = std::move(onOpComplete);
                opCompleteCallbackData->topic = nullptr;
                ByteBuf topicFilterBuf = aws_byte_buf_from_c_str(topicFilter);
                ByteCursor topicFilterCur = aws_byte_cursor_from_buf(&topicFilterBuf);

                uint16_t packetId = aws_mqtt_client_connection_unsubscribe(
                    m_underlyingConnection, &topicFilterCur, s_onOpComplete, opCompleteCallbackData);

                if (!packetId)
                {
                    Crt::Delete(opCompleteCallbackData, m_owningClient->allocator);
                }

                return packetId;
            }