public static <Z> ImmutableSortedSet<Z> copyOf(Z[] elements) {
    throw new UnsupportedOperationException();
  }

  private static final long serialVersionUID = 0xcafebabe;

          Function<? super T, ? extends V> valueFunction,
          BinaryOperator<V> mergeFunction) {
    throw new UnsupportedOperationException();
  }

  private static final long serialVersionUID = 0xcafebabe;

  private void readObject(ObjectInputStream stream) throws InvalidObjectException {
    throw new InvalidObjectException("Use SerializedForm");
  }

  private static final long serialVersionUID = 0xcafebabe;