question: private void reloadCacheWithNewValue ( final Long newValue ) { final long newValueAsPrimitive = newValue == null ? getCacheUpdatePeriod ( ) : newValue ; LOG . debug ( "invoking {} listeners" , cacheUpdatePeriodListeners . size ( ) ) ; for ( final PropertyChangeListener listener : cacheUpdatePeriodListeners ) { final PropertyChangeEvent event = new PropertyChangeEvent ( this , "cache" , getCacheUpdatePeriod ( ) , newValueAsPrimitive ) ; listener . propertyChange ( event ) ; } }
target:  Notify all listeners about cachePeriod property changed. If passed newValue is null, the oldValue is taken as new value. This is the case when the reloadCache is invoked.