return (delegate != null)
          ? delegate.keySet().remove(o)
          : CompactHashMap.this.removeHelper(o) != NOT_FOUND;
    }

    @Override
    public Iterator<K> iterator() {
      return keySetIterator();
    }

    @Override
    public Spliterator<K> spliterator() {
      if (needsAllocArrays()) {

  }

  final Set<K> unmodifiableKeySet() {
    return new AbstractSet<K>() {
      @Override
      public UnmodifiableIterator<K> iterator() {
        Iterator<Entry<K, V>> entryIterator = backingMap.entrySet().iterator();

        return new UnmodifiableIterator<K>() {
          @Override
          public boolean hasNext() {
            return entryIterator.hasNext();
          }

 */
package org.codelibs.core.collection;

import java.util.Iterator;

import org.codelibs.core.exception.ClUnsupportedOperationException;

/**
 * An empty {@link Iterator}.
 *
 * @author higa
 * @param <T> the element type
 */
public class EmptyIterator<T> implements Iterator<T> {

    /**
     * Creates an {@link EmptyIterator}.
     */
    public EmptyIterator() {

    return adjacentNodes();
  }

  @Override
  public Set<N> successors() {
    return adjacentNodes();
  }

  @Override
  public Iterator<EndpointPair<N>> incidentEdgeIterator(N thisNode) {
    return Iterators.transform(
        adjacentNodeValues.keySet().iterator(),
        (N incidentNode) -> EndpointPair.unordered(thisNode, incidentNode));
  }

  @Override
  public @Nullable V value(N node) {

  }

  /**
   * Returns the value of the given {@code int} as a {@code long}, when treated as unsigned.
   *
   * <p><b>Java 8+ users:</b> use {@link Integer#toUnsignedLong(int)} instead.
   */
  public static long toLong(int value) {
    return value & INT_MASK;
  }

  /**
   * Returns the {@code int} value that, when treated as unsigned, is equal to {@code value}, if
   * possible.
   *

  final transient Collection<E> delegate;

  ForwardingImmutableCollection(Collection<E> delegate) {
    this.delegate = delegate;
  }

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

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

  @Override

import java.util.ListIterator;
import org.jspecify.annotations.Nullable;

/**
 * A list iterator which forwards all its method calls to another list iterator. Subclasses should
 * override one or more methods to modify the behavior of the backing iterator as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *

interface GraphConnections<N, V> {

  Set<N> adjacentNodes();

  Set<N> predecessors();

  Set<N> successors();

  /**
   * Returns an iterator over the incident edges.
   *
   * @param thisNode The node that this all of the connections in this class are connected to.
   */
  Iterator<EndpointPair<N>> incidentEdgeIterator(N thisNode);

  /**

    }

    @Override
    public Iterator<K> iterator() {
      return keySetIterator();
    }

    @Override
    public void clear() {
      CompactHashMap.this.clear();
    }
  }

  Iterator<K> keySetIterator() {
    Map<K, V> delegate = delegateOrNull();
    if (delegate != null) {
      return delegate.keySet().iterator();
    }
    return new Itr<K>() {
      @Override

        // Test iterator
        Iterator<Map<String, Object>> iterator = qrList.iterator();
        assertTrue(iterator.hasNext());
        assertEquals(doc1, iterator.next());
        assertTrue(iterator.hasNext());
        assertEquals(doc2, iterator.next());
        assertFalse(iterator.hasNext());

        // Test listIterator