question: public synchronized void removeDiscoveryListener ( DiscoveryListener l ) { if ( terminated ) { throw new IllegalStateException ( "discovery terminated" ) ; } int index = listeners . indexOf ( l ) ; if ( index != - 1 ) listeners . remove ( index ) ; }
target:  Remove a DiscoveryListener from the listener set. It does nothing if the DiscoveryListener does not exist in the the listener set.