code: @Override
      public Object getValue(Integer window) {
          synchronized (this) {
              long v = unflushed.get();
              for (MeanMeter meter : meterMap.values()) {
                  meter.mark(v);
              }
              unflushed.addAndGet(-v);
  
              return meterMap.get(window).getOneMinuteRate();
          }
      }
docs: {@inheritDoc}