expectAddFailure(sortedMultiset.headMultiset(b.getElement(), OPEN), b);
    expectAddFailure(sortedMultiset.headMultiset(a.getElement(), CLOSED), c);
    expectAddFailure(sortedMultiset.headMultiset(a.getElement(), CLOSED), b);
    expectAddFailure(sortedMultiset.headMultiset(a.getElement(), OPEN), c);
    expectAddFailure(sortedMultiset.headMultiset(a.getElement(), OPEN), b);
    expectAddFailure(sortedMultiset.headMultiset(a.getElement(), OPEN), a);
  }

    expectAddFailure(sortedMultiset.headMultiset(b.getElement(), OPEN), b);
    expectAddFailure(sortedMultiset.headMultiset(a.getElement(), CLOSED), c);
    expectAddFailure(sortedMultiset.headMultiset(a.getElement(), CLOSED), b);
    expectAddFailure(sortedMultiset.headMultiset(a.getElement(), OPEN), c);
    expectAddFailure(sortedMultiset.headMultiset(a.getElement(), OPEN), b);
    expectAddFailure(sortedMultiset.headMultiset(a.getElement(), OPEN), a);
  }

  @CheckForNull
  public Entry<E> pollLastEntry() {
    throw new UnsupportedOperationException();
  }

  @Override
  public SortedMultiset<E> headMultiset(@ParametricNullness E upperBound, BoundType boundType) {
    return Multisets.unmodifiableSortedMultiset(delegate().headMultiset(upperBound, boundType));
  }

  @Override
  public SortedMultiset<E> subMultiset(
      @ParametricNullness E lowerBound,

                }

                if (to == Bound.INCLUSIVE) {
                  multiset = multiset.headMultiset(lastInclusive, BoundType.CLOSED);
                } else if (to == Bound.EXCLUSIVE) {
                  multiset = multiset.headMultiset(lastExclusive, BoundType.OPEN);
                }

                return multiset;
              }
            })