/guava/guava/src/com/google/common/collect/Sets.java
return set1.contains ( object ) || set2.contains ( object ) ;
@Override public Stream<E> parallelStream() { return stream().parallel(); } @Override public boolean contains(@CheckForNull Object object) { <extra_id_0> } @Override public <S extends Set<E>> S copyInto(S set) { set.addAll(set1); set.addAll(set2); return set;