question: @ Override public final void sample ( ) { synchronized ( _lock ) { long count = _count . get ( ) ; long lastCount = _lastAvgCount ; _lastAvgCount = count ; long sum = _sum . get ( ) ; double lastSum = _lastAvgSum ; _lastAvgSum = sum ; if ( count == lastCount ) _value = 0 ; else _value = _scale * ( sum - lastSum ) / ( double ) ( count - lastCount ) ; } }
target:  Return the probe's next average.