guava/src/com/google/common/collect/ImmutableSortedSet.java
public static <E extends Comparable<? super E>> ImmutableSortedSet<E> copyOf(E[] elements) {
    return construct(Ordering.natural(), elements.length, elements.clone());
  }
public static <E extends Comparable<? super E>> ImmutableSortedSet<E> copyOf(E[] elements) {
    return construct(Ordering.natural(), elements.length, elements.clone());
  }
Returns an immutable sorted set containing the given elements sorted by their natural ordering.
When multiple elements are equivalent according to {@link Comparable#compareTo}, only the first
one specified is included.

@throws NullPointerException if any of {@code elements} is null
@since 3.0