docs: @Override
      public boolean addSync() throws ResourceException {
  
          final boolean isTracingEnabled = TraceComponent.isAnyTracingEnabled();
  
          if (isTracingEnabled && tc.isEntryEnabled()) {
              Tr.entry(this, tc, "addSync");
          }
  
          UOWCoordinator uowCoord = mcWrapper.getUOWCoordinator();
  
          if (uowCoord == null) {
              java.lang.IllegalStateException e = new java.lang.IllegalStateException("addSync: illegal state exception. uowCoord is null");
              Object[] parms = new Object[] { "addSync", e };
              Tr.error(tc, "ILLEGAL_STATE_EXCEPTION_J2CA0079", parms);
              if (isTracingEnabled && tc.isEntryEnabled())
                  Tr.exit(this, tc, "addSync", e);
              throw e;
          }
  
          try {
              if (mcWrapper.isConnectionSynchronizationProvider()) {
                  throw new NotSupportedException();
              }
  
              /*
               * This code will remain here just in case we run into this
               * case. We should not be isEnlistmentDisabled in this code.
               *
               * Log a message and return, if isEnlistmentDisabled is true.
               */
              if (mcWrapper.isEnlistmentDisabled()) {
  
                  if (isTracingEnabled && tc.isDebugEnabled()) {
                      Tr.debug(this, tc, "Managed connection isEnlistmentDisabled is true.");
                      Tr.debug(this, tc, "Returning without registering.");
                  }
  
                  if (isTracingEnabled && tc.isEntryEnabled()) {
                      Tr.exit(this, tc, "addSync", false);
                  }
  
                  return false;
  
              }
  
              /*
               * Use our XATransactionWrapper
               */
              EmbeddableWebSphereTransactionManager tranMgr = mcWrapper.pm.connectorSvc.transactionManager;
              tranMgr.registerSynchronization(uowCoord, this);
  
          } catch (Exception e) {
              com.ibm.ws.ffdc.FFDCFilter.processException(
                                                          e,
                                                          "com.ibm.ejs.j2c.XATransactionWrapper.addSync",
                                                          "237",
                                                          this);
              Object[] parms = new Object[] { "addSync", e, "ResourceException" };
              Tr.error(tc, "REGISTER_WITH_SYNCHRONIZATION_EXCP_J2CA0026", parms);
              ResourceException re = new ResourceException("addSync: caught Exception");
              re.initCause(e);
              if (isTracingEnabled && tc.isEntryEnabled())
                  Tr.exit(this, tc, "addSync", e);
              throw re;
          }
  
          if (isTracingEnabled && tc.isEntryEnabled())
              Tr.exit(this, tc, "addSync", true);
          return true;
      }