/guava/guava/src/com/google/common/collect/AbstractMapBasedMultimap.java
return new SortedKeySet( ( ( SortedMap<K, Collection<V>>) ( map) ) )  map) ;
return new NavigableKeySet ( ( NavigableMap<K, Collection<V>> ) map ) ;
@Override Set<K> createKeySet() { return new KeySet(map); } final Set<K> createMaybeNavigableKeySet() { if (map instanceof NavigableMap) { <extra_id_0> } else if (map instanceof SortedMap) { return new SortedKeySet((SortedMap<K, Collection<V>>) map); } else { return new KeySet(map); } }