import org.jspecify.annotations.Nullable;

/**
 * This class provides a skeletal implementation of the {@code Iterator} interface for sequences
 * whose next element can always be derived from the previous element. Null elements are not
 * supported, nor is the {@link #remove()} method.
 *
 * <p>Example:
 *
 * {@snippet :
 * Iterator<Integer> powersOfTwo =
 *     new AbstractSequentialIterator<Integer>(1) {

      }
    }
    val outputStream = socket.getOutputStream()
    val inputStream = socket.getInputStream()
    val reader = Http2Reader(inputStream.source().buffer(), client)
    val outFramesIterator: Iterator<OutFrame> = outFrames.iterator()
    val outBytes = bytesOut.readByteArray()
    var nextOutFrame: OutFrame? = null
    for (i in 0 until frameCount) {
      if (nextOutFrame == null && outFramesIterator.hasNext()) {

    /**
     * @throws Exception
     */
    @Test
    public void testForEach() throws Exception {
        final StringReader reader = new StringReader("aaa\nbbb\nccc\n");
        for (final String line : LineIterator.iterable(reader)) {
            System.out.println(line);
        }
    }

    POST_ORDER {
      @Override
      <T> Iterable<T> view(T root, TreeTraverser<T> viewer) {
        return viewer.postOrderTraversal(root);
      }
    },
    BREADTH_FIRST {
      @Override
      <T> Iterable<T> view(T root, TreeTraverser<T> viewer) {
        return viewer.breadthFirstTraversal(root);
      }
    };

    abstract <T> Iterable<T> view(T root, TreeTraverser<T> viewer);
  }

      this.multiset = multiset;
    }

    @Override
    final SortedMultiset<E> multiset() {
      return multiset;
    }

    @Override
    public Iterator<E> iterator() {
      return Multisets.elementIterator(multiset().entrySet().iterator());
    }

    @Override
    public Comparator<? super E> comparator() {
      return multiset().comparator();
    }

    @Override

            putAll(map);
        }
    }

    @Override
    public String toString() {
        StringBuilder buffer = new StringBuilder("ManagedVersionMap (" + size() + " entries)\n");
        Iterator<String> iter = keySet().iterator();
        while (iter.hasNext()) {
            String key = iter.next();
            buffer.append(key).append('=').append(get(key));
            if (iter.hasNext()) {
                buffer.append('\n');

  private Dispatcher dispatcher;

  public void testPerThreadQueuedDispatcher() {
    dispatcher = Dispatcher.perThreadDispatchQueue();
    dispatcher.dispatch(1, integerSubscribers.iterator());

    assertThat(dispatchedSubscribers)
        .containsExactly(
            i1,
            i2,
            i3, // Integer subscribers are dispatched to first.
            s1,

    }

    @Override
    public SortedMultiset<E> descendingMultiset() {
      return new StandardDescendingMultiset() {

        @Override
        Iterator<Entry<E>> entryIterator() {
          return backingMultiset.descendingMultiset().entrySet().iterator();
        }
      };
    }

    @Override
    public NavigableSet<E> elementSet() {
      return new StandardElementSet();
    }

    @Override

    public E element() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.element();
    }

    @Override
    public Iterator<E> iterator() {
      // We explicitly don't lock for iterator()
      assertFalse(Thread.holdsLock(mutex));
      return delegate.iterator();
    }

    @Override
    public int size() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.size();
    }

    Set<Entry<Integer, String>> entries = map.entrySet();
    Iterator<Entry<Integer, String>> iterator = entries.iterator();
    Entry<Integer, String> entry = iterator.next();
    entry.setValue("two"); // changes the iterator's current entry value
    assertEquals("two", map.get(1));
    assertEquals(Integer.valueOf(1), map.inverse().get("two"));
    iterator.remove(); // removes the updated entry
    assertTrue(map.isEmpty());
  }