public <R extends Set<T>> R unionInto(SetIterable<? extends T> set, R targetSet) { return SetIterables.unionInto(this, set, targetSet); }
public ImmutableSortedSet<T> union(SetIterable<? extends T> set) { return SetIterables.unionInto(this, set, TreeSortedSet.<T>newSet(this.comparator())) .toImmutable(); }