android/guava/src/com/google/common/collect/ImmutableSortedMultiset.java
@SuppressWarnings("unchecked")
  public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(E e1, E e2) {
    return copyOf(Ordering.natural(), Arrays.asList(e1, e2));
  }
@SuppressWarnings("unchecked")
  public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(E e1, E e2) {
    return copyOf(Ordering.natural(), Arrays.asList(e1, e2));
  }
Returns an immutable sorted multiset containing the given elements sorted by their natural
ordering.

@throws NullPointerException if any element is null