public void testSingletonMultisetNearby() {
    assertNull(sortedMultiset.headMultiset(e0(), OPEN).lastEntry());
    assertNull(sortedMultiset.tailMultiset(e0(), OPEN).lastEntry());

    assertEquals(a, sortedMultiset.headMultiset(e0(), CLOSED).lastEntry());
    assertEquals(a, sortedMultiset.tailMultiset(e0(), CLOSED).firstEntry());
  }

  @CollectionSize.Require(ONE)
  public void testSingletonMultisetLast() {

  @Override
  protected Map<Integer, UnhashableObject> makePopulatedMap() {
    Unhashables unhashables = new Unhashables();
    return ImmutableMap.of(0, unhashables.e0());
  }

    return ImmutableMap.of();
  }

  @Override
  protected Map<Integer, UnhashableObject> makePopulatedMap() {
    Unhashables unhashables = new Unhashables();
    return ImmutableMap.of(0, unhashables.e0(), 1, unhashables.e1(), 2, unhashables.e2());
  }

  @Override
  protected Integer getKeyNotInPopulatedMap() {
    return 3;
  }

  @Override
  protected UnhashableObject getValueNotInPopulatedMap() {

  @CollectionFeature.Require(absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testCreateWithDuplicates() {
    E[] array = createSamplesArray();
    array[1] = e0();
    collection = getSubjectGenerator().create(array);

    expectContents(array);
  }

    }

    @Override
    public SampleElements<Entry<V, K>> samples() {
      SampleElements<Entry<K, V>> samples = generator.samples();
      return new SampleElements<>(
          reverse(samples.e0()),
          reverse(samples.e1()),
          reverse(samples.e2()),
          reverse(samples.e3()),
          reverse(samples.e4()));
    }

    private Entry<V, K> reverse(Entry<K, V> entry) {

    return ImmutableMap.of();
  }

  @Override
  protected Map<Integer, UnhashableObject> makePopulatedMap() {
    Unhashables unhashables = new Unhashables();
    return ImmutableMap.of(0, unhashables.e0(), 1, unhashables.e1(), 2, unhashables.e2());
  }

  @Override
  protected Integer getKeyNotInPopulatedMap() {
    return 3;
  }

  @Override
  protected UnhashableObject getValueNotInPopulatedMap() {

  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_supportedPresent() {
    assertTrue(getMap().remove(k0(), v0()));
    expectMissing(e0());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemove_supportedPresentKeyWrongValue() {
    assertFalse(getMap().remove(k0(), v3()));
    expectUnchanged();
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_supportedPresent() {
    assertTrue(getMap().remove(k0(), v0()));
    expectMissing(e0());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemove_supportedPresentKeyWrongValue() {
    assertFalse(getMap().remove(k0(), v3()));
    expectUnchanged();
  }

    assertEscaping(e, "%7F", '\u007f'); // del
    assertEscaping(e, "%C2%80", '\u0080'); // xx-00010,x-000000
    assertEscaping(e, "%DF%BF", '\u07ff'); // xx-11111,x-111111
    assertEscaping(e, "%E0%A0%80", '\u0800'); // xxx-0000,x-100000,x-00,0000
    assertEscaping(e, "%EF%BF%BF", '\uffff'); // xxx-1111,x-111111,x-11,1111
    assertUnicodeEscaping(e, "%F0%90%80%80", '\uD800', '\uDC00');

  @CollectionFeature.Require(SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  public void testAdd_supportedPresent() {
    assertFalse("add(present) should return false", getSet().add(e0()));
    expectUnchanged();
  }

  @CollectionFeature.Require(value = {SUPPORTS_ADD, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testAdd_supportedNullPresent() {