@Override
  public UnmodifiableIterator<E> iterator() {
    return Iterators.unmodifiableIterator(delegate.iterator());
  }

  @Override
  public boolean contains(@Nullable Object object) {
    return object != null && delegate.contains(object);
  }

  @Override
  public boolean containsAll(Collection<?> targets) {
    return delegate.containsAll(targets);
  }

  @Override
  public int size() {

        @SuppressWarnings("rawtypes") // using raw types to avoid a bug in our nullness checker :(
        InternalEntry entry = map.getEntry(sample);
        if (entry != null) {
          Object canonical = entry.getKey();
          if (canonical != null) { // only matters if weak/soft keys are used
            // The compiler would know this is safe if not for our use of raw types (see above).
            @SuppressWarnings("unchecked")

 * methods of the delegate. For example, overriding {@link #add} alone <b>will not</b> change the
 * behavior of {@link #offer} which can lead to unexpected behavior. In this case, you should
 * override {@code offer} as well, either providing your own implementation, or delegating to the
 * provided {@code standardOffer} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code

   *
   * @param element the element to add one occurrence of; may be null only if explicitly allowed by
   *     the implementation
   * @return {@code true} always, since this call is required to modify the multiset, unlike other
   *     {@link Collection} types
   * @throws NullPointerException if {@code element} is null and this implementation does not permit
   *     null elements

/**
 * Provides similar behavior to {@link String#intern} for any immutable type. Common implementations
 * are available from the {@link Interners} class.
 *
 * <p>Note that {@code String.intern()} has some well-known performance limitations, and should
 * generally be avoided. Prefer {@link Interners#newWeakInterner} or another {@code Interner}
 * implementation even for {@code String} interning.
 *
 * @author Kevin Bourrillion

   * #hashCode()} to forward to this implementation.
   *
   * @since 7.0
   */
  protected int standardHashCode() {
    K k = getKey();
    V v = getValue();
    return ((k == null) ? 0 : k.hashCode()) ^ ((v == null) ? 0 : v.hashCode());
  }

  /**
   * A sensible definition of {@link #toString} in terms of {@link #getKey} and {@link #getValue}.

     * allowing the CAS below to succeed.
     */
    Thread currentThread = Thread.currentThread();
    if (!compareAndSet(null, currentThread)) {
      return; // someone else has run or is running.
    }

    boolean run = !isDone();
    T result = null;
    Throwable error = null;
    try {
      if (run) {
        result = runInterruptibly();

        return LegacyLocalRepositoryManager.overlay(localRepository, legacySupport.getRepositorySession(), null);
    }

    private void injectSession1(RepositoryRequest request, MavenSession session) {
        if (session != null) {
            request.setOffline(session.isOffline());
            request.setForceUpdate(session.getRequest().isUpdateSnapshots());
        }
    }

    ms.add("b");
    ms.add(null);
    ms.add("a");
    ms.add("b");
    ms.add(null, 2);

    assertThat(ms).containsExactly(null, null, null, "a", "b", "b").inOrder();
    assertEquals(3, ms.count(null));

    SortedSet<@Nullable String> elementSet = ms.elementSet();
    assertEquals(null, elementSet.first());
    assertEquals("b", elementSet.last());

  internal var errorException: IOException? = null

  init {
    if (headers != null) {
      check(!isLocallyInitiated) { "locally-initiated streams shouldn't have headers yet" }
      headersQueue += headers
    } else {
      check(isLocallyInitiated) { "remotely-initiated streams should have headers" }
    }
  }

  /**
   * Returns true if this stream is open. A stream is open until either: