question: private void deleteInstance ( EntryClass eclass ) { int idx = entryClasses . indexOf ( eclass ) ; eclass = ( EntryClass ) entryClasses . get ( idx ) ; int num = eclass . getNumInstances ( ) - 1 ; if ( num == 0 ) entryClasses . remove ( idx ) ; eclass . setNumInstances ( num ) ; }
target:  Delete an instance of the EntryClass, and remove the class from entryClasses if this is the last such instance.