docs: private final synchronized boolean _decrementTotal(int sizeInBytes)
      {
          boolean doCallback = false;
  
          // Decrement the count before we check for the watermark being reached
          // (510343)
          _countTotal--;
          if (_watermarkCountLow == _countTotal)
          {
              // guaranteed to go below....
              doCallback = true;
          }
  
          boolean wasAboveLowLimit = (_countTotalBytes >= _watermarkBytesLow);
  
          _countTotalBytes = _countTotalBytes - sizeInBytes;
  
          if (wasAboveLowLimit && _countTotalBytes < _watermarkBytesLow)
          {
              doCallback = true;
          }
  
          return doCallback;
      }