code: public StopWatch freeze()
      {
          StopWatch sw = new StopWatch( m_tag, m_message);
          sw.m_startNanos = m_startNanos;
          sw.m_stopNanos = m_stopNanos != 0 ? m_stopNanos : System.nanoTime();
          sw.m_creation = m_creation;
          sw.m_count = m_count;
          return sw;
      }
docs: TODO: Should probably return a FrozenStopWatch