@Override
    public Comparator<? super E> comparator() {
      return multiset().comparator();
    }

    @Override
    public SortedSet<E> subSet(@ParametricNullness E fromElement, @ParametricNullness E toElement) {
      return multiset().subMultiset(fromElement, CLOSED, toElement, OPEN).elementSet();
    }

    @Override
    public SortedSet<E> headSet(@ParametricNullness E toElement) {

  @Override
  public NavigableSet<E> subSet(
      E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
    return new SafeTreeSet<>(
        delegate.subSet(
            checkValid(fromElement), fromInclusive, checkValid(toElement), toInclusive));
  }

  @Override
  public SortedSet<E> subSet(E fromElement, E toElement) {
    return subSet(fromElement, true, toElement, false);
  }

  @Override

   * keeps the original {@code fromElement}.
   */
  @Override
  public ImmutableSortedSet<E> tailSet(E fromElement) {
    return tailSet(fromElement, true);
  }

  /**
   * @since 12.0
   */
  @Override
  public ImmutableSortedSet<E> tailSet(E fromElement, boolean inclusive) {
    return tailSetImpl(checkNotNull(fromElement), inclusive);
  }

  /*

        return fromSpliterator.tryAdvance(
            fromElement -> action.accept(function.apply(fromElement)));
      }

      @Override
      public void forEachRemaining(Consumer<? super OutElementT> action) {
        fromSpliterator.forEachRemaining(fromElement -> action.accept(function.apply(fromElement)));
      }

      @Override

    return delegate().last();
  }

  @Override
  public SortedSet<E> subSet(@ParametricNullness E fromElement, @ParametricNullness E toElement) {
    return delegate().subSet(fromElement, toElement);
  }

  @Override
  public SortedSet<E> tailSet(@ParametricNullness E fromElement) {
    return delegate().tailSet(fromElement);
  }

  /**

        return fromSpliterator.tryAdvance(
            fromElement -> action.accept(function.apply(fromElement)));
      }

      @Override
      public void forEachRemaining(Consumer<? super OutElementT> action) {
        fromSpliterator.forEachRemaining(fromElement -> action.accept(function.apply(fromElement)));
      }

      @Override

  ImmutableSortedSet<E> subSetImpl(
      E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
    return tailSetImpl(fromElement, fromInclusive).headSetImpl(toElement, toInclusive);
  }

  @Override
  ImmutableSortedSet<E> tailSetImpl(E fromElement, boolean inclusive) {
    return getSubSet(tailIndex(fromElement, inclusive), size());
  }

  int tailIndex(E fromElement, boolean inclusive) {

          sortedMap().subMap(fromElement, fromInclusive, toElement, toInclusive));
    }

    @Override
    public NavigableSet<K> tailSet(@ParametricNullness K fromElement) {
      return tailSet(fromElement, true);
    }

    @Override
    public NavigableSet<K> tailSet(@ParametricNullness K fromElement, boolean inclusive) {
      return new NavigableKeySet(sortedMap().tailMap(fromElement, inclusive));
    }
  }

    }

    @Override
    public String toString() {
      return standardToString();
    }

    @Override
    public SortedSet<T> subSet(T fromElement, T toElement) {
      return standardSubSet(fromElement, toElement);
    }

    @Override
    public @Nullable T lower(T e) {
      return standardLower(e);
    }

    @Override
    public @Nullable T floor(T e) {

  ContiguousSet<C> headSetImpl(C toElement, boolean inclusive) {
    return this;
  }

  @Override
  ContiguousSet<C> subSetImpl(
      C fromElement, boolean fromInclusive, C toElement, boolean toInclusive) {
    return this;
  }

  @Override
  ContiguousSet<C> tailSetImpl(C fromElement, boolean fromInclusive) {
    return this;
  }

  @Override
  public boolean contains(@Nullable Object object) {
    return false;
  }