/guava/guava/src/com/google/common/collect/Sets.java
while ( itr1.hasNext ( ) ) { E elem1 = itr1.next ( ) ;
final Iterator<? extends E> itr1 = set1.iterator(); final Iterator<? extends E> itr2 = set2.iterator(); return new AbstractIterator<E>() { @Override @CheckForNull public E computeNext() { <extra_id_0> if (!set2.contains(elem1)) { return elem1; } } while (itr2.hasNext()) { E elem2 = itr2.next();