"rawtypes", // https://github.com/google/guava/issues/989
    "NonApiType", // acts as a direct substitute for a constructor call
  })
  public static <E extends Comparable> TreeSet<E> newTreeSet(Iterable<? extends E> elements) {
    TreeSet<E> set = newTreeSet();
    Iterables.addAll(set, elements);
    return set;
  }

  /**
   * Creates a <i>mutable</i>, empty {@code TreeSet} instance with the given comparator.
   *

          .put(SortedSet.class, ImmutableSortedSet.of())
          .put(ImmutableSortedSet.class, ImmutableSortedSet.of())
          .put(NavigableSet.class, Sets.unmodifiableNavigableSet(Sets.newTreeSet()))
          .put(Map.class, ImmutableMap.of())
          .put(ImmutableMap.class, ImmutableMap.of())
          .put(SortedMap.class, ImmutableSortedMap.of())

   * implemented in terms of sortedDelegate (except comparator()).
   */
  ImmutableSortedSet(Comparator<? super E> comparator) {
    this(Sets.newTreeSet(comparator));
  }

  ImmutableSortedSet(SortedSet<E> sortedDelegate) {
    super(sortedDelegate);
    this.sortedDelegate = Collections.unmodifiableSortedSet(sortedDelegate);
  }

  @Override

          .put(SortedSet.class, ImmutableSortedSet.of())
          .put(ImmutableSortedSet.class, ImmutableSortedSet.of())
          .put(NavigableSet.class, Sets.unmodifiableNavigableSet(Sets.newTreeSet()))
          .put(Map.class, ImmutableMap.of())
          .put(ImmutableMap.class, ImmutableMap.of())
          .put(SortedMap.class, ImmutableSortedMap.of())

    return generateTreeSet(freshElement);
  }

  @Generates
  static <E extends Comparable<? super E>> TreeSet<E> generateTreeSet(E freshElement) {
    TreeSet<E> set = Sets.newTreeSet();
    set.add(freshElement);
    return set;
  }

  @Generates
  static <E extends Comparable<? super E>> ImmutableSortedSet<E> generateImmutableSortedSet(
      E freshElement) {

    return generateTreeSet(freshElement);
  }

  @Generates
  static <E extends Comparable<? super E>> TreeSet<E> generateTreeSet(E freshElement) {
    TreeSet<E> set = Sets.newTreeSet();
    set.add(freshElement);
    return set;
  }

  @Generates
  static <E extends Comparable<? super E>> ImmutableSortedSet<E> generateImmutableSortedSet(
      E freshElement) {