derivedSuites.add(createSubsetSuite(parentBuilder, Bound.EXCLUSIVE, Bound.NO_BOUND));
      derivedSuites.add(createSubsetSuite(parentBuilder, Bound.EXCLUSIVE, Bound.EXCLUSIVE));
      derivedSuites.add(createSubsetSuite(parentBuilder, Bound.EXCLUSIVE, Bound.INCLUSIVE));
      derivedSuites.add(createSubsetSuite(parentBuilder, Bound.INCLUSIVE, Bound.INCLUSIVE));
    }

      derivedSuites.add(createSubMultisetSuite(parentBuilder, Bound.INCLUSIVE, Bound.NO_BOUND));
      derivedSuites.add(createSubMultisetSuite(parentBuilder, Bound.INCLUSIVE, Bound.EXCLUSIVE));
      derivedSuites.add(createSubMultisetSuite(parentBuilder, Bound.INCLUSIVE, Bound.INCLUSIVE));
    }

    return derivedSuites;
  }

  private TestSuite createSubMultisetSuite(

  /** The endpoint value <i>is not</i> considered part of the set ("exclusive"). */
  OPEN(false),
  CLOSED(true);

  final boolean inclusive;

  BoundType(boolean inclusive) {
    this.inclusive = inclusive;
  }

  /** Returns the bound type corresponding to a boolean value for inclusivity. */
  static BoundType forBoolean(boolean inclusive) {
    return inclusive ? CLOSED : OPEN;
  }

    }

    @Override
    public NavigableSet<E> tailSet(@ParametricNullness E fromElement, boolean inclusive) {
      return new NavigableElementSet<>(
          multiset().tailMultiset(fromElement, BoundType.forBoolean(inclusive)));
    }
  }

  private static <E extends @Nullable Object> E getElementOrThrow(@Nullable Entry<E> entry) {
    if (entry == null) {

      for (List<Integer> contents : SAMPLE_INPUTS) {
        for (int i = 0; i < 10; i++) {
          for (boolean inclusive : ImmutableList.of(true, false)) {
            assertEquals(
                filter(createUnfiltered(contents).headSet(i, inclusive), EVEN),
                filter(createUnfiltered(contents), EVEN).headSet(i, inclusive));
          }
        }
      }
    }

    public void testNavigableTailSet() {

      derivedSuites.add(createSubsetSuite(parentBuilder, Bound.EXCLUSIVE, Bound.NO_BOUND));
      derivedSuites.add(createSubsetSuite(parentBuilder, Bound.EXCLUSIVE, Bound.EXCLUSIVE));
      derivedSuites.add(createSubsetSuite(parentBuilder, Bound.EXCLUSIVE, Bound.INCLUSIVE));
      derivedSuites.add(createSubsetSuite(parentBuilder, Bound.INCLUSIVE, Bound.INCLUSIVE));
    }

      derivedSuites.add(createSubmapSuite(parentBuilder, Bound.EXCLUSIVE, Bound.NO_BOUND));
      derivedSuites.add(createSubmapSuite(parentBuilder, Bound.EXCLUSIVE, Bound.EXCLUSIVE));
      derivedSuites.add(createSubmapSuite(parentBuilder, Bound.EXCLUSIVE, Bound.INCLUSIVE));
      derivedSuites.add(createSubmapSuite(parentBuilder, Bound.INCLUSIVE, Bound.INCLUSIVE));
    }

    return derivedSuites;

  /** The endpoint value <i>is not</i> considered part of the set ("exclusive"). */
  OPEN(false),
  CLOSED(true);

  final boolean inclusive;

  BoundType(boolean inclusive) {
    this.inclusive = inclusive;
  }

  /** Returns the bound type corresponding to a boolean value for inclusivity. */
  static BoundType forBoolean(boolean inclusive) {
    return inclusive ? CLOSED : OPEN;
  }

    return subSet(fromElement, true, toElement, false);
  }

  @Override
  public NavigableSet<E> headSet(@ParametricNullness E toElement, boolean inclusive) {
    return delegate().headSet(toElement, inclusive);
  }

  /**
   * A sensible definition of {@link #headSet(Object)} in terms of the {@link #headSet(Object,

      return subMap(
          Range.range(
              fromKey, BoundType.forBoolean(fromInclusive),
              toKey, BoundType.forBoolean(toInclusive)));
    }

    @Override
    public NavigableMap<Cut<C>, Range<C>> headMap(Cut<C> toKey, boolean inclusive) {
      return subMap(Range.upTo(toKey, BoundType.forBoolean(inclusive)));
    }

    @Override