code: public synchronized void pushMetric(final MetricsRecord mr) {
      if (changed) 
        mr.setMetric(getName(), value);
      changed = false;
    }
docs: Push the metric to the mr.
  The metric is pushed only if it was updated since last push
  
  Note this does NOT push to JMX
  (JMX gets the info via {@link #get()}
  
  @param mr