* When multiple elements are equivalent according to {@code compareTo()}, only the first one
   * specified is included. To create a copy of a {@code SortedSet} that preserves the comparator,
   * call {@link #copyOfSorted} instead. This method iterates over {@code elements} at most once.
   *
   * <p>Note that if {@code s} is a {@code Set<String>}, then {@code ImmutableSortedSet.copyOf(s)}

    checkNotNull(mergeFunction);
    return Collectors.collectingAndThen(
        Collectors.toMap(
            keyFunction, valueFunction, mergeFunction, () -> new TreeMap<K, V>(comparator)),
        ImmutableSortedMap::copyOfSorted);
  }

  // unsafe, comparator() returns a comparator on the specified type
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableSortedMap<K, V> of() {

   * When multiple elements are equivalent according to {@code compareTo()}, only the first one
   * specified is included. To create a copy of a {@code SortedSet} that preserves the comparator,
   * call {@link #copyOfSorted} instead. This method iterates over {@code elements} at most once.
   *
   * <p>Note that if {@code s} is a {@code Set<String>}, then {@code ImmutableSortedSet.copyOf(s)}

    checkNotNull(valueFunction);
    checkNotNull(mergeFunction);
    return collectingAndThen(
        toMap(keyFunction, valueFunction, mergeFunction, () -> new TreeMap<K, V>(comparator)),
        ImmutableSortedMap::copyOfSorted);
  }

  static <T extends @Nullable Object, K, V> Collector<T, ?, ImmutableBiMap<K, V>> toImmutableBiMap(
      Function<? super T, ? extends K> keyFunction,
      Function<? super T, ? extends V> valueFunction) {

    SortedSet<String> set = ImmutableSortedSet.copyOfSorted(input);
    assertThat(set).containsExactly("a", "in", "jumped", "over", "quick", "the").inOrder();
  }

  public void testCopyOfSorted_natural_comparator() {
    SortedSet<String> input = Sets.newTreeSet(asList("in", "the", "quick", "jumped", "over", "a"));
    SortedSet<String> set = ImmutableSortedSet.copyOfSorted(input);
    assertSame(Ordering.natural(), set.comparator());

    return copyOfInternal(comparator, elements);
  }

  // We use NATURAL_ORDER only if the input was already using natural ordering.
  @SuppressWarnings("unchecked")
  public static <E> ImmutableSortedSet<E> copyOfSorted(SortedSet<E> sortedSet) {
    Comparator<? super E> comparator = sortedSet.comparator();
    if (comparator == null) {
      comparator = (Comparator<? super E>) NATURAL_ORDER;
    }

        .thenReturn(Ordering.<Comparable<String>>natural());
    when(toCopy.entrySet()).thenReturn(entrySet);
    ImmutableSortedMultiset<String> unused = ImmutableSortedMultiset.copyOfSorted(toCopy);
    assertTrue(entrySet.toArrayCalled);
  }

  private static class IntegerDiv10 implements Comparable<IntegerDiv10> {
    final int value;

    IntegerDiv10(int value) {

  }

  /**
   * Returns an immutable sorted multiset containing the given elements sorted by their natural
   * ordering. To create a copy of a {@code SortedMultiset} that preserves the comparator, call
   * {@link #copyOfSorted} instead. This method iterates over {@code elements} at most once.
   *
   * <p>Note that if {@code s} is a {@code Multiset<String>}, then {@code

 * usually include:
 *
 * <ul>
 *   <li>Static methods named {@code of}, accepting an explicit list of elements or entries.
 *   <li>Static methods named {@code copyOf} (or {@code copyOfSorted}), accepting an existing
 *       collection whose contents should be copied.
 *   <li>A static nested {@code Builder} class which can be used to populate a new immutable
 *       instance.
 * </ul>
 *

   * undocumented and subject to change.
   *
   * @throws NullPointerException if any key or value in {@code map} is null
   */
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableSortedMap<K, V> copyOfSorted(SortedMap<K, ? extends V> map) {
    Comparator<? super K> comparator = map.comparator();
    if (comparator == null) {
      // If map has a null comparator, the keys should have a natural ordering,