this.delegate = delegate;
    }

    @Override
    E get(int index) {
      return entries.get(index).getElement();
    }

    @Override
    public boolean contains(@CheckForNull Object object) {
      return delegate.contains(object);
    }

    @Override
    boolean isPartialView() {
      return true;
    }

    @Override
    public int size() {
      return entries.size();

      }
    }
  }

  private static void assertContains(String expectedSubstring, String actual) {
    // TODO(kevinb): use a Truth assertion here
    if (!actual.contains(expectedSubstring)) {
      fail("expected <" + actual + "> to contain <" + expectedSubstring + ">");
    }
  }

  public void testElementSet_contains() {
    assertTrue(
        "multiset.elementSet().contains(present) returned false",
        getMultiset().elementSet().contains(e0()));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testEntrySet_contains() {
    assertTrue(
        "multiset.entrySet() didn't contain [present, 1]",
        getMultiset().entrySet().contains(Multisets.immutableEntry(e0(), 1)));
  }

    testDecodes(base64(), "Zg==", "f"); // proper padding length
    testDecodes(base64(), "Zg===", "f");
    testDecodes(base64(), "Zg====", "f");
  }

  public void testBase64InvalidDecodings() {
    // These contain bytes not in the decodabet.
    assertFailsToDecode(base64(), "A\u007f", "Unrecognized character: 0x7f");
    assertFailsToDecode(base64(), "Wf2!", "Unrecognized character: !");
    // This sentence just isn't base64() encoded.

    assertTrue(
        "addAll(somePresent) should return true",
        collection.addAll(MinimalCollection.of(e3(), e0())));
    assertTrue("should contain " + e3(), collection.contains(e3()));
    assertTrue("should contain " + e0(), collection.contains(e0()));
  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  public void testAddAll_unsupportedSomePresent() {
    try {

  /**
   * The collection must not throw {@code NullPointerException} on calls such as {@code
   * contains(null)} or {@code remove(null)}, but instead must return a simple {@code false}.
   */
  ALLOWS_NULL_QUERIES,
  ALLOWS_NULL_VALUES(ALLOWS_NULL_QUERIES),

  /**
   * Indicates that a collection disallows certain elements (other than {@code null}, whose validity

          return optional.orNull();
        }
      };

  /**
   * Sets.cartesianProduct doesn't allow sets that contain null, but we want null to mean "don't
   * call the associated CacheBuilder method" - that is, get the default CacheBuilder behavior. This
   * method wraps the elements in the input sets (which may contain null) as Optionals, calls
   * Sets.cartesianProduct with those, then transforms the result to unwrap the Optionals.
   */

  public boolean containsKey(@CheckForNull Object key) {
    return seekByKey(key, smearedHash(key)) != null;
  }

  /**
   * Returns {@code true} if this BiMap contains an entry whose value is equal to {@code value} (or,
   * equivalently, if this inverse view contains a key that is equal to {@code value}).
   *
   * <p>Due to the property that values in a BiMap are unique, this will tend to execute in
   * faster-than-linear time.
   *

 * @param <S> the source or sink type
 * @param <T> the data type (byte[] or String)
 * @author Colin Decker
 */
public interface SourceSinkFactory<S, T> {

  /**
   * Returns the data to expect the source or sink to contain given the data that was used to create
   * the source or written to the sink. Typically, this will just return the input directly, but in
   * some cases it may alter the input. For example, if the factory returns a sliced view of a

   *
   * <p>This implementation is highly efficient when {@code elements} is itself a {@link Multiset}.
   *
   * @param elements the elements that the multiset should contain
   */
  public static <E extends @Nullable Object> HashMultiset<E> create(
      Iterable<? extends E> elements) {
    HashMultiset<E> multiset = create(Multisets.inferDistinctElements(elements));