final public void decrement(long decVal) {
        if (enabled) { // synchronize the update of lastValue
            lastSampleTime = updateIntegral();
            synchronized (this) {
                current -= decVal;
            }
            updateWaterMark();
        } else {
            current -= decVal;
        }
    }
final public void decrement ( long decVal ) { if ( enabled ) { lastSampleTime = updateIntegral ( ) ; synchronized ( this ) { current -= decVal ; } updateWaterMark ( ) ; } else { current -= decVal ; } }
/*
Synchronizable: counter is "updated" with the input value