code: @Override
      public void setNonPersistentMapping(String nonPersistentMapping) throws JMSException {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.entry(this, tc, "setNonPersistentMapping", nonPersistentMapping);
  
          if (nonPersistentMapping == null) {
              throw (JMSException) JmsErrorUtils.newThrowable(
                                                              JMSException.class,
                                                              "INVALID_VALUE_CWSIA0261",
                                                              new Object[] { "nonPersistentMapping", null },
                                                              tc
                              );
          }
  
          if (nonPersistentMapping.equals(ApiJmsConstants.MAPPING_BEST_EFFORT_NONPERSISTENT) ||
              nonPersistentMapping.equals(ApiJmsConstants.MAPPING_EXPRESS_NONPERSISTENT) ||
              nonPersistentMapping.equals(ApiJmsConstants.MAPPING_RELIABLE_NONPERSISTENT) ||
              nonPersistentMapping.equals(ApiJmsConstants.MAPPING_RELIABLE_PERSISTENT) ||
              nonPersistentMapping.equals(ApiJmsConstants.MAPPING_ASSURED_PERSISTENT) ||
              nonPersistentMapping.equals(ApiJmsConstants.MAPPING_NONE)) {
              jcaManagedConnectionFactory.setNonPersistentMapping(nonPersistentMapping);
          }
          else if (nonPersistentMapping.equals(ApiJmsConstants.MAPPING_AS_SIB_DESTINATION)) {
              jcaManagedConnectionFactory.setNonPersistentMapping(ApiJmsConstants.MAPPING_NONE);
          }
          else {
              throw (JMSException) JmsErrorUtils.newThrowable(
                                                              JMSException.class,
                                                              "INVALID_VALUE_CWSIA0261",
                                                              new Object[] { "nonPersistentMapping", nonPersistentMapping },
                                                              tc
                              );
          }
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.exit(this, tc, "setNonPersistentMapping");
      }
docs: default non persistent mapping is EXPRESS_NONPERSISTENT, null non persistent mapping is
  not valid.