/guava/android/guava/src/com/google/common/collect/Maps.java
this.set = checkNotNull( set) ;this.function = checkNotNull( function) ;
this.function = checkNotNull ( function ) ;
final Function<? super K, V> function; Set<K> backingSet() { return set; } AsMapView(Set<K> set, Function<? super K, V> function) { this.set = checkNotNull(set); <extra_id_0> } @Override public Set<K> createKeySet() { return removeOnlySet(backingSet()); } @Override