code: public static void rcvXAOpen(CommsByteBuffer request, Conversation conversation,
                                  int requestNumber, boolean allocatedFromBufferPool,
                                  boolean partOfExchange)
     {
        if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) SibTr.entry(tc, "rcvXAOpen",
                                             new Object[]
                                             {
                                                request,
                                                conversation,
                                                ""+requestNumber,
                                                ""+allocatedFromBufferPool,
                                                ""+partOfExchange
                                              });
  
        short connectionObjectId = request.getShort();
        int clientTransactionId = request.getInt();
  
        if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled())
        {
           SibTr.debug(tc, "Connection Object ID", connectionObjectId);
           SibTr.debug(tc, "Transaction ID", clientTransactionId);
        }
  
        try
        {
           conversation.send(poolManager.allocate(),
                             JFapChannelConstants.SEG_XAOPEN_R,
                             requestNumber,
                             JFapChannelConstants.PRIORITY_MEDIUM,
                             true,
                             ThrottlingPolicy.BLOCK_THREAD,
                             null);
        }
        catch (SIException e)
        {
           FFDCFilter.processException(e,
                                       CLASS_NAME + ".rcvXAOpen",
                                       CommsConstants.STATICCATXATRANSACTION_XAOPEN_01);
  
           SibTr.error(tc, "COMMUNICATION_ERROR_SICO2027", e);
        }
  
        request.release(allocatedFromBufferPool);
  
        if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) SibTr.exit(tc, "rcvXAOpen");
     }
docs: Gets the XAResource from the SICoreConnection and stores it in the
  object store.
  
  Fields:
  
  BIT16    ConnectionObjectId
  
  @param request
  @param conversation
  @param requestNumber
  @param allocatedFromBufferPool
  @param partOfExchange