return new TreeSet<E>(contents);
      }
    },
    UnmodifiableSetImpl {
      @Override
      public <E extends Comparable<E>> Set<E> create(Collection<E> contents) {
        return Collections.unmodifiableSet(new HashSet<E>(contents));
      }
    },
    SynchronizedSetImpl {
      @Override
      public <E extends Comparable<E>> Set<E> create(Collection<E> contents) {

    }

    @Override
    public boolean addAll(Collection<? extends V> collection) {
      addAll(0, collection);
      return true;
    }

    @CanIgnoreReturnValue
    @Override
    public boolean addAll(int index, Collection<? extends V> elements) {
      checkNotNull(elements);
      checkPositionIndex(index, 0);

    }

    @Override
    public boolean addAll(Collection<? extends V> collection) {
      addAll(0, collection);
      return true;
    }

    @CanIgnoreReturnValue
    @Override
    public boolean addAll(int index, Collection<? extends V> elements) {
      checkNotNull(elements);
      checkPositionIndex(index, 0);

    synchronized (collection) { // to allow Collections.synchronized* tests to pass
      Helpers.assertEqualIgnoringOrder(
          getSampleElements(), Arrays.asList(collection.stream().toArray()));
    }
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testStreamToArrayKnownOrder() {
    synchronized (collection) { // to allow Collections.synchronized* tests to pass

        return result;
    }

    @Override
    public Collection<ResolutionScope> buildResolutionScopes(InternalScopeManager internalScopeManager) {
        Collection<DependencyScope> allDependencyScopes = internalScopeManager.getDependencyScopeUniverse();
        Collection<DependencyScope> nonTransitiveDependencyScopes =

  }

  protected Collection<Method> suppressForHashMap() {
    return Collections.emptySet();
  }

  protected Collection<Method> suppressForHashtable() {
    return Collections.emptySet();
  }

  protected Collection<Method> suppressForLinkedHashMap() {
    return Collections.emptySet();
  }

  protected Collection<Method> suppressForTreeMapNatural() {
    return Collections.emptySet();
  }

   * words, for the default {@code expectContents()} implementation, the number of occurrences of
   * each given element has increased by one since the test collection was created, and the number
   * of occurrences of all other elements has not changed.
   *
   * <p>Note: This means that a test like the following will fail if {@code collection} is a {@code
   * Set}:
   *
   * <pre>

  }

  public void testCopyOf_collection_empty() {
    // "<String>" is required to work around a javac 1.5 bug.
    Collection<String> c = MinimalCollection.<String>of();
    Multiset<String> multiset = ImmutableSortedMultiset.copyOf(c);
    assertTrue(multiset.isEmpty());
  }

  public void testCopyOf_collection_oneElement() {
    Collection<String> c = MinimalCollection.of("a");

    extends SetMultimap<K, V> {
  // Following Javadoc copied from Multimap.

  /**
   * Returns a collection view of all values associated with a key. If no mappings in the multimap
   * have the provided key, an empty collection is returned.
   *
   * <p>Changes to the returned collection will update the underlying multimap, and vice versa.
   *

    assertTrue("removeIf(x -> true) should return true", collection.removeIf(x -> true));
    expectContents();
  }

  @CollectionFeature.Require({SUPPORTS_ITERATOR_REMOVE, FAILS_FAST_ON_CONCURRENT_MODIFICATION})
  @CollectionSize.Require(SEVERAL)
  public void testRemoveIfSomeMatchesConcurrentWithIteration() {
    try {
      Iterator<E> iterator = collection.iterator();
      assertTrue(collection.removeIf(Predicate.isEqual(samples.e0())));