question: public static < T > boolean areSetsIdentical ( final Set < T > set1 , final Set < T > set2 ) { if ( set1 == set2 ) return true ; if ( CollectionUtil . size ( set1 ) != CollectionUtil . size ( set2 ) ) return false ; if ( CollectionUtil . isEmpty ( set1 ) ) return true ; for ( final T t : set1 ) if ( ! set2 . contains ( t ) ) return false ; return true ; }
target:  returns true iff all of the items on each set exist on the other set .