code: public void set(long val) // V5: add()
      {
          if (current == val) {
              lastSampleTime = System.currentTimeMillis();
              return;
          }
          if (enabled) {
              long curTime = updateIntegral();
              setWaterMark(curTime, val);
          } else {
              current = val;
          }
      }
docs: /*
  Non-Synchronizable: counter is "replaced" with the input value. Caller should synchronize.
  (no need to synchronize because val is calculated elsewhere)