code: @Override
      public void setReadAhead(String value) throws JMSException {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.entry(this, tc, "setReadAhead", value);
  
          // Check for null then ensure that the value is one of the permitted constants.
          if ((value != null)
              && ((ApiJmsConstants.READ_AHEAD_DEFAULT.equals(value))
                  || (ApiJmsConstants.READ_AHEAD_ON.equals(value))
                  || (ApiJmsConstants.READ_AHEAD_OFF.equals(value))
              )) {
              jcaManagedConnectionFactory.setReadAhead(value);
          }
          else {
              throw (JMSException) JmsErrorUtils.newThrowable(
                                                              JMSException.class,
                                                              "INVALID_VALUE_CWSIA0261",
                                                              new Object[] { "readAhead", value },
                                                              tc
                              );
          }
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.exit(this, tc, "setReadAhead");
      }
docs: /*
  (non-Javadoc)
  
  @see com.ibm.websphere.sib.api.jms.JmsConnectionFactory#setReadAhead(java.lang.String)