code: protected byte[] getXID()
      {
          if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled()) {
              trace.entry(this, cclass
                          , "getXID"
                              );
              trace.exit(this, cclass
                         , "getXID"
                         , "returns logicalUnitOfWork.XID=" + logicalUnitOfWork.XID + "(byte[])"
                              );
          } // if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled())
          return logicalUnitOfWork.XID;
      }
docs: <p>
  Returns the XID identifying the transaction or null if has not been set.
  
  @return byte[] The Xopen identifier of the transaction, or null.
  </p>