question: public synchronized void release ( Object obj ) { if ( obj == null ) { throw new NullPointerException ( "ResourcePool: managed resource " + "cannot be null" ) ; } if ( alloced . remove ( obj ) == false ) { throw new IllegalArgumentException ( "ResourcePool: unknown resource " + obj ) ; } freeResource ( obj ) ; notifyAll ( ) ; }
target:  Release a resource back to the pool after its use is completed.