question: protected void fireClusterChange ( long timestamp , String type , String message ) { if ( listeners != null && ! listeners . isEmpty ( ) ) { ClusterEvent event = new ClusterEvent ( this , timestamp , type , message ) ; Vector targets ; synchronized ( this ) { targets = ( Vector ) listeners . clone ( ) ; } Enumeration e = targets . elements ( ) ; while ( e . hasMoreElements ( ) ) { ClusterEventListener l = ( ClusterEventListener ) e . nextElement ( ) ; l . changeCluster ( event ) ; } } }
target:  Fire a ClusterChangeEvent to all registered listeners 