/guava/android/guava/src/com/google/common/collect/Sets.java
if ( !set2.contains( elem1) ) {
if ( !set1.contains ( elem2 ) ) {
if (!set2.contains(elem1)) { return elem1; } } while (itr2.hasNext()) { E elem2 = itr2.next(); <extra_id_0> return elem2; } } return endOfData(); } };