question: public void fireLayer ( int type , Layer [ ] layers ) { if ( logger . isLoggable ( Level . FINE ) ) { logger . fine ( "calling setLayers on " + size ( ) + " objects" ) ; } if ( isEmpty ( ) ) return ; LayerEvent evt = new LayerEvent ( source , type , layers ) ; for ( LayerListener listener : this ) { listener . setLayers ( evt ) ; } }
target:  Send a layer event to all registered listeners.