protected Map<Object, Integer> makePopulatedMap() {
    Colliders colliders = new Colliders();
    return ImmutableMap.of(
        colliders.e0(), 0,
        colliders.e1(), 1,
        colliders.e2(), 2,
        colliders.e3(), 3);
  }

  @Override
  protected Object getKeyNotInPopulatedMap() {
    return new Colliders().e4();
  }

  @Override
  protected Integer getValueNotInPopulatedMap() {
    return 4;
  }

    return getMultiset().setCount(element, getMultiset().count(element), count);
  }

  private void assertSetCountNegativeOldCount() {
    try {
      getMultiset().setCount(e3(), -1, 1);
      fail("calling setCount() with a negative oldCount should throw IllegalArgumentException");
    } catch (IllegalArgumentException expected) {
    }
  }

  // Negative oldCount.

      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) {
      checkNotNull(entry);
      return mapEntry(entry.getValue(), entry.getKey());
    }

    return ImmutableSortedSet.of(e1, e2, e3);
  }

  @Override
  protected <E extends Comparable<? super E>> SortedSet<E> of(E e1, E e2, E e3, E e4) {
    return ImmutableSortedSet.of(e1, e2, e3, e4);
  }

  @Override
  protected <E extends Comparable<? super E>> SortedSet<E> of(E e1, E e2, E e3, E e4, E e5) {

    }

    public void test_encodeUrl_valid() {
        String url = "http://TEST.com/hoge/;jsessionid?p=id&test=テスト&u=18718&v=123%3d#test";
        String result = "http://TEST.com/hoge/;jsessionid?p=id&test=%E3%83%86%E3%82%B9%E3%83%88&u=18718&v=123%3d#test";
        assertEquals(result, htmlTransformer.encodeUrl(url, "UTF-8"));

        url = ".-*_:/+%=&?#[]@~!$'(),;";
        result = ".-*_:/+%=&?#[]@~!$'(),;";

  protected abstract <E extends Comparable<? super E>> Set<E> of(E e1, E e2, E e3);

  protected abstract <E extends Comparable<? super E>> Set<E> of(E e1, E e2, E e3, E e4);

  protected abstract <E extends Comparable<? super E>> Set<E> of(E e1, E e2, E e3, E e4, E e5);

  protected abstract <E extends Comparable<? super E>> Set<E> of(
      E e1, E e2, E e3, E e4, E e5, E e6, E... rest);

  }

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

  @Override
  public CollectionSize getCollectionSize() {
    return collectionSize;
  }

  @Override

        assertNull(systemHelper.encodeUrlFilter(path));

        path = "abc";
        assertEquals(path, systemHelper.encodeUrlFilter(path));

        path = "あいう";
        assertEquals("%E3%81%82%E3%81%84%E3%81%86", systemHelper.encodeUrlFilter(path));

        path = "[]^$.*+?,{}|%\\";
        assertEquals(path, systemHelper.encodeUrlFilter(path));

        systemHelper.filterPathEncoding = null;

                v3(),
                (oldV, newV) -> {
                  throw new AssertionFailedError(
                      "Should not call merge function if key was absent");
                }));
    expectAdded(e3());
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testMappedToNull() {
    initMapWithNullValue();
    assertEquals(

  }

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

  @Override
  public CollectionSize getCollectionSize() {
    return collectionSize;
  }

  @Override