import org.jspecify.annotations.Nullable;

/**
 * This class provides a skeletal implementation of the {@link ListIterator} interface across a
 * fixed number of elements that may be retrieved by position. It does not support {@link #remove},
 * {@link #set}, or {@link #add}.
 *
 * @author Jared Levy
 */
@GwtCompatible
abstract class AbstractIndexedListIterator<E extends @Nullable Object>

    }
  }

  Set<K> keySet;

  @Override
  public Set<K> keySet() {
    // does not impact recency ordering
    Set<K> ks = keySet;
    return (ks != null) ? ks : (keySet = new KeySet(this));
  }

  Collection<V> values;

  @Override
  public Collection<V> values() {
    // does not impact recency ordering
    Collection<V> vs = values;

    // If we clip the safe range used during the per-character tests so it is
    // below the values of characters in surrogate pairs, this cannot occur.
    // This approach does mean that we break out of the fast path code in cases
    // where we don't strictly need to, but this situation will almost never
    // occur in practice.
    if (safeMin >= Character.MIN_HIGH_SURROGATE) {

 * As a stream ID is scoped to a single HTTP/2 connection, implementations which target multiple
 * connections should expect repetition of stream IDs.
 *
 * Return true to request cancellation of a pushed stream.  Note that this does not guarantee
 * future frames won't arrive on the stream ID.
 */
interface PushObserver {
  /**
   * Describes the request that the server intends to push a response for.
   *

      return "Functions.identity()";
    }
  }

  /**
   * Returns a function which performs a map lookup. The returned function throws an {@link
   * IllegalArgumentException} if given a key that does not exist in the map. See also {@link
   * #forMap(Map, Object)}, which returns a default value in this case.
   *
   * <p>Note: if {@code map} is a {@link com.google.common.collect.BiMap BiMap} (or can be one), you

    try {
      assertEquals(0, Queues.drain(q, ImmutableList.of(), 0, 10, MILLISECONDS));
    } catch (InterruptedException e) {
      throw new AssertionError();
    }

    // but does the wait actually occurs?
    @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
    Future<?> possiblyIgnoredError = threadPool.submit(new Interrupter(currentThread()));
    try {

   * collection is set to {@code null}. This is useful in determining the length of the collection
   * <i>only</i> if the caller knows that the collection does not contain any null elements.
   *
   * <p>This method returns the elements in the order they are returned by the collection's
   * iterator.
   *
   * <p>TODO(kevinb): support concurrently modified collections?

     * and then. This means that we're silently swallowing an exception -- maybe even an Error. But
     * this is no worse than what FutureTask does in that situation. Additionally, because the
     * Future was cancelled, its listeners have been run, so its consumers will not hang.
     *

     * opened if it is not and should be closed with {@link #close()} when no longer
     * needed.
     *
     * Closing the context should cancel a pending notify request, but that does not seem to work reliable in all
     * implementations.
     *
     * Changes in between these calls (as long as the file is open) are buffered by the server, so iteratively calling

   * Asserts that the given object is non-null, with a better failure message than {@link
   * TestCase#assertNull(String, Object)}.
   *
   * <p>The {@link TestCase} version (which is from JUnit 3) produces a failure message that does
   * not include the value of the object.
   *
   * @since 33.4.0
   */
  public static void assertNull(String message, Object object) {
    assertEquals(message, null, object);
  }