// derive values for inclusive filtering from the input samples
      SampleElements<Entry<K, V>> samples = delegate.samples();
      List<Entry<K, V>> samplesList =
          Arrays.asList(samples.e0(), samples.e1(), samples.e2(), samples.e3(), samples.e4());
      Collections.sort(samplesList, entryComparator);
      this.firstInclusive = samplesList.get(0).getKey();

  }

  protected final E e0() {
    return samples.e0();
  }

  protected final E e1() {
    return samples.e1();
  }

  protected final E e2() {
    return samples.e2();
  }

  protected final E e3() {
    return samples.e3();
  }

  protected final E e4() {
    return samples.e4();
  }

    }

    @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 generator.create(elements.toArray());
  }

  @Override
  public Collection<E> getSampleElements(int howMany) {
    SampleElements<E> samples = samples();
    List<E> allSampleElements =
        Arrays.asList(samples.e0(), samples.e1(), samples.e2(), samples.e3(), samples.e4());
    return new ArrayList<>(allSampleElements.subList(0, howMany));
  }

  @Override
  public CollectionSize getCollectionSize() {

  /**
   * Returns an element less than the {@link #samples()} but greater than {@link
   * #belowSamplesLesser()}.
   */
  E belowSamplesGreater();

  /**
   * Returns an element greater than the {@link #samples()} but less than {@link
   * #aboveSamplesGreater()}.
   */
  E aboveSamplesLesser();

  /**
   * Returns an element greater than the {@link #samples()} and greater than {@link
   * #aboveSamplesLesser()}.
   */

  /**
   * Returns an element less than the {@link #samples()} but greater than {@link
   * #belowSamplesLesser()}.
   */
  E belowSamplesGreater();

  /**
   * Returns an element greater than the {@link #samples()} but less than {@link
   * #aboveSamplesGreater()}.
   */
  E aboveSamplesLesser();

  /**
   * Returns an element greater than the {@link #samples()} and greater than {@link
   * #aboveSamplesLesser()}.
   */

  SortedMap<K, V> create(Object... elements);

  /**
   * Returns an entry with a key less than the keys of the {@link #samples()} and less than the key
   * of {@link #belowSamplesGreater()}.
   */
  Entry<K, V> belowSamplesLesser();

  /**
   * Returns an entry with a key less than the keys of the {@link #samples()} but greater than the
   * key of {@link #belowSamplesLesser()}.
   */
  Entry<K, V> belowSamplesGreater();

  /**

    return generator.create(elements.toArray());
  }

  @Override
  public Collection<E> getSampleElements(int howMany) {
    SampleElements<E> samples = samples();
    List<E> allSampleElements =
        Arrays.asList(samples.e0(), samples.e1(), samples.e2(), samples.e3(), samples.e4());
    return new ArrayList<>(allSampleElements.subList(0, howMany));
  }

  @Override
  public CollectionSize getCollectionSize() {

  @CollectionSize.Require(absent = ZERO)
  public void testRemoveIf_sometimesTrue() {
    assertTrue(
        "removeIf(isEqual(present)) should return true",
        collection.removeIf(Predicate.isEqual(samples.e0())));
    expectMissing(samples.e0());
  }

  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemoveIf_allPresent() {

      // derive values for inclusive filtering from the input samples
      SampleElements<Entry<K, V>> samples = delegate.samples();
      List<Entry<K, V>> samplesList =
          Arrays.asList(samples.e0(), samples.e1(), samples.e2(), samples.e3(), samples.e4());
      Collections.sort(samplesList, entryComparator);
      this.firstInclusive = samplesList.get(0).getKey();