question: public void add ( K key , V [ ] items ) { Set < V > values = map . get ( key ) ; if ( values == null ) { values = ( sorted ? new TreeSet < V > ( ) : new HashSet < V > ( ) ) ; map . put ( key , values ) ; } values . addAll ( Arrays . asList ( items ) ) ; }
target:  Adds all items to the set of values associated with the key