ContiguousSet<C> subSetImpl(
      C fromElement, boolean fromInclusive, C toElement, boolean toInclusive) {
    if (fromElement.compareTo(toElement) == 0 && !fromInclusive && !toInclusive) {
      // Range would reject our attempt to create (x, x).
      return new EmptyContiguousSet<>(domain);
    }
    return intersectionInCurrentDomain(
        Range.range(
            fromElement, BoundType.forBoolean(fromInclusive),

    }

    @Override
    public NavigableSet<E> tailSet(@ParametricNullness E fromElement, boolean inclusive) {
      return forward.headSet(fromElement, inclusive).descendingSet();
    }

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

    @SuppressWarnings("unchecked")
    @Override

  public SortedMultiset<E> subMultiset(
      @ParametricNullness E fromElement,
      BoundType fromBoundType,
      @ParametricNullness E toElement,
      BoundType toBoundType) {
    // These are checked elsewhere, but NullPointerTester wants them checked eagerly.
    checkNotNull(fromBoundType);
    checkNotNull(toBoundType);
    return tailMultiset(fromElement, fromBoundType).headMultiset(toElement, toBoundType);
  }

  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;
  }

    }

    @Override
    ImmutableSortedSet<C> subSetImpl(
        C fromElement, boolean fromInclusive, C toElement, boolean toInclusive) {
      if (!fromInclusive && !toInclusive && Range.compareOrThrow(fromElement, toElement) == 0) {
        return ImmutableSortedSet.of();
      }
      return subSet(
          Range.range(
              fromElement, BoundType.forBoolean(fromInclusive),