docs: private void parseSegmentStartPayload(WsByteBuffer contextBuffer)
     {
        if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) SibTr.entry(this, tc, "parseSegmentStartPayload", contextBuffer);
        if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) JFapUtils.debugTraceWsByteBufferInfo(this, tc, contextBuffer, "contextBuffer");
        if (unparsedPayloadData == null)
        {
           if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) SibTr.debug(this, tc, "allocating unparsed payload data buffe, size="+segmentedTransmissionHeaderFields[primaryHeaderFields.priority].totalLength);  // D191832.1
  
           unparsedPayloadData =
              allocateWsByteBuffer((int)segmentedTransmissionHeaderFields[primaryHeaderFields.priority].totalLength, primaryHeaderFields.isPooled);                                      // D191832.1
           unparsedPayloadData.position(0);
           unparsedPayloadData.limit((int)segmentedTransmissionHeaderFields[primaryHeaderFields.priority].totalLength);                                                                  // D191832.1
        }
  
        if (state != STATE_ERROR)
        {
           int amountCopied =
              JFapUtils.copyWsByteBuffer(contextBuffer, unparsedPayloadData, transmissionPayloadRemaining);
           transmissionPayloadRemaining -= amountCopied;
  
           if (inFlightSegmentedTransmissions[primaryHeaderFields.priority] != null)
           {
              throwable = new SIConnectionLostException(nls.getFormattedMessage("TRANSPARSER_PROTOCOLERROR_SICJ0053", new Object[] {connection.remoteHostAddress, connection.chainName}, "TRANSPARSER_PROTOCOLERROR_SICJ0053"));   // D226223
              // This FFDC was generated because our peer sent us a duplicate start of a segmented
              // transmission.  I.e. we already had a partial segmented transmission built for a
              // given priority level when our peer sent us the start of another.
              FFDCFilter.processException(throwable, "com.ibm.ws.sib.jfapchannel.impl.InboundTransmissionParser", JFapChannelConstants.INBOUNDXMITPARSER_PARSESSPAYLOAD_01, getFormattedBytes(contextBuffer));   // D267629
              state = STATE_ERROR;
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) SibTr.debug(this, tc, "Received the start of a segmented transmission whilst already processing a segmented transmission at the same priority level");
           }
           else
           {
              needMoreData = (contextBuffer.remaining() == 0);
              if (!needMoreData)
              {
                 inFlightSegmentedTransmissions[primaryHeaderFields.priority] = unparsedPayloadData;
                 // begin F193735.3
                 if (type == Conversation.ME)
                    meReadBytes += unparsedPayloadData.remaining();
                 else if (type == Conversation.CLIENT)
                    clientReadBytes -= unparsedPayloadData.remaining();
                 // end F193735.3
                 reset();
              }
           }
        }
  
        if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) SibTr.exit(this, tc, "parseSegmentStartPayload");
     }