code: public void contextChange(int typeOfChange, UOWCoordinator UOW) throws IllegalStateException
      {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              Tr.entry(tc, "contextChange : " + typeOfChange + ", " + UOW);
  
          String changeType = "Unknown";
          // Determine the Tx change type and process
          switch (typeOfChange) {
              case PRE_BEGIN:
                  changeType = "Pre_Begin";
                  break;
  
              case POST_BEGIN:
                  changeType = "Post_Begin";
                  handleUserTxCallback(true);
                  break;
  
              case PRE_END:
                  changeType = "Pre_End";
                  break;
  
              case POST_END:
                  changeType = "Post_End";
                  handleUserTxCallback(false);
                  break;
          }
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              Tr.exit(tc, "contextChange : " + changeType);
      }
docs: /*
  (non-Javadoc)
  
  @see com.ibm.ws.Transaction.UOWCallback#contextChange(int,
  com.ibm.ws.Transaction.UOWCoordinator)