@Override
  public SampleElements<Entry<AnEnum, String>> samples() {
    return new SampleElements<>(
        Helpers.mapEntry(AnEnum.A, "January"),
        Helpers.mapEntry(AnEnum.B, "February"),
        Helpers.mapEntry(AnEnum.C, "March"),
        Helpers.mapEntry(AnEnum.D, "April"),
        Helpers.mapEntry(AnEnum.E, "May"));
  }

  @Override
  public final Map<AnEnum, String> create(Object... entries) {

    List<?> list = Arrays.asList("a", "b");
    Helpers.assertContains(list, "a");
    Helpers.assertContains(list, "b");

    try {
      Helpers.assertContains(list, "c");
      throw new Error();
    } catch (AssertionFailedError expected) {
    }
  }

  public void testAssertContainsAllOf() {
    List<?> list = Arrays.asList("a", "a", "b", "c");
    Helpers.assertContainsAllOf(list, "a");

   */
  public static Method[] getHoleMethods() {
    return new Method[] {
      Helpers.getMethod(NavigableSetNavigationTester.class, "testLowerHole"),
      Helpers.getMethod(NavigableSetNavigationTester.class, "testFloorHole"),
      Helpers.getMethod(NavigableSetNavigationTester.class, "testCeilingHole"),
      Helpers.getMethod(NavigableSetNavigationTester.class, "testHigherHole"),
    };
  }

  @Override
  public SampleElements<Entry<String, String>> samples() {
    return new SampleElements<>(
        Helpers.mapEntry("one", "January"),
        Helpers.mapEntry("two", "February"),
        Helpers.mapEntry("three", "March"),
        Helpers.mapEntry("four", "April"),
        Helpers.mapEntry("five", "May"));
  }

  @Override
  public final BiMap<String, String> create(Object... entries) {

        Maps.immutableEnumMap(ImmutableMap.of(AnEnum.C, "c", AnEnum.A, "a", AnEnum.E, "e"));

    assertThat(map.entrySet())
        .containsExactly(
            Helpers.mapEntry(AnEnum.A, "a"),
            Helpers.mapEntry(AnEnum.C, "c"),
            Helpers.mapEntry(AnEnum.E, "e"))
        .inOrder();
  }

  public void testToImmutableEnumMap() {

  @Override
  public Entry<String, String> belowSamplesLesser() {
    return Helpers.mapEntry("!! a", "below view");
  }

  @Override
  public Entry<String, String> belowSamplesGreater() {
    return Helpers.mapEntry("!! b", "below view");
  }

  @Override
  public Entry<String, String> aboveSamplesLesser() {
    return Helpers.mapEntry("~~ a", "above view");
  }

  @Override

    expectMissing(Helpers.mapEntry(k0(), v0()));
    assertEquals(getNumElements() - 1, multimap().size());
    assertFalse(multimap().containsEntry(k0(), v0()));
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRetainAllPropagatesToMultimap() {
    multimap().entries().retainAll(Collections.singleton(Helpers.mapEntry(k0(), v0())));

    try {
      assertFalse(getMap().entrySet().contains(Helpers.mapEntry(IncomparableType.INSTANCE, v0())));
    } catch (ClassCastException acceptable) {
      // allowed by the spec
    }
  }

  public void testContainsEntryWithIncomparableValue() {
    try {
      assertFalse(getMap().entrySet().contains(Helpers.mapEntry(k0(), IncomparableType.INSTANCE)));
    } catch (ClassCastException acceptable) {

  @Override
  public Entry<String, String> belowSamplesLesser() {
    return Helpers.mapEntry("!! a", "below view");
  }

  @Override
  public Entry<String, String> belowSamplesGreater() {
    return Helpers.mapEntry("!! b", "below view");
  }

  @Override
  public Entry<String, String> aboveSamplesLesser() {
    return Helpers.mapEntry("~~ a", "above view");
  }

  @Override

public class MultimapKeysTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  @CollectionSize.Require(SEVERAL)
  public void testKeys() {
    resetContainer(
        Helpers.mapEntry(k0(), v0()), Helpers.mapEntry(k0(), v1()), Helpers.mapEntry(k1(), v0()));
    Multiset<K> keys = multimap().keys();
    assertEquals(2, keys.count(k0()));
    assertEquals(1, keys.count(k1()));
    assertEquals(3, keys.size());