code: public void setMode( String mode )
      {
          Mode m = Mode.valueOf( mode );
  
          if( m != null )
              m_mode = m;
      }
docs: You may set the mode for the PeriodicalLog.  This can be
  <ul>
  <li>QUIET - when you don't want any logging</li>
  <li>JMX_ONLY - when you want JMX only to show up</li>
  <li>LOG_ONLY - when you want just log, not JMX</li>
  <li>ALL - When you want both JMX and log</li>
  </ul>
  <p>
  By default PeriodicalLog is in ALL mode.
  
  @param mode One of the above strings.  If the string cannot
  be recognized, the value is ignored.