question: public void purgeAndNotifyRemovedLayers ( ) { ArrayList < Layer > rLayers = new ArrayList < Layer > ( removedLayers ) ; removedLayers . clear ( ) ; if ( rLayers . isEmpty ( ) ) { return ; } for ( Layer layer : rLayers ) { layer . removed ( this ) ; } if ( Debug . debugging ( "helpgc" ) ) { System . gc ( ) ; } }
target:  Clear the vector containing all of the removed layers, and let those layers know they have been removed from the map.