/guava/guava/src/com/google/common/collect/HashBiMap.java
super ( HashBiMap.this ) ;
@Override public Set<K> keySet() { return new KeySet(); } private final class KeySet extends Maps.KeySet<K, V> { KeySet() { <extra_id_0> } @Override public Iterator<K> iterator() { return new Itr<K>() { @Override @ParametricNullness