start = System.currentTimeMillis();
        for (Iterator<Map.Entry<String, Object>> i = hmap.entrySet().iterator(); i.hasNext();) {
            i.next();
        }
        System.out.println("HashMap iteration:" + (System.currentTimeMillis() - start));

        start = System.currentTimeMillis();
        for (Iterator<Map.Entry<String, Object>> i = amap.entrySet().iterator(); i.hasNext();) {
            i.next();
        }

  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testKeySetIteratorRemove() {
    int initialSize = getNumElements();
    Iterator<K> iterator = getMap().keySet().iterator();
    iterator.next();
    iterator.remove();
    assertEquals(initialSize - 1, getMap().size());
    assertEquals(initialSize - 1, getMap().inverse().size());
  }

import com.google.common.collect.TestExceptions.SomeUncheckedException;
import com.google.common.testing.GcFinalization;
import java.lang.ref.WeakReference;
import java.util.Iterator;
import java.util.NoSuchElementException;
import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@code AbstractIterator}.
 *

  /**
   * A sensible definition of {@link #firstEntry()} in terms of {@code entrySet().iterator()}.
   *
   * <p>If you override {@link #entrySet()}, you may wish to override {@link #firstEntry()} to
   * forward to this implementation.
   */
  protected @Nullable Entry<E> standardFirstEntry() {
    Iterator<Entry<E>> entryIterator = entrySet().iterator();
    if (!entryIterator.hasNext()) {
      return null;
    }

    assertEquals(rangeSet.asDescendingSetOfRanges().isEmpty(), rangeSet.isEmpty());
    assertEquals(!rangeSet.asRanges().iterator().hasNext(), rangeSet.isEmpty());
    assertEquals(!rangeSet.asDescendingSetOfRanges().iterator().hasNext(), rangeSet.isEmpty());

    List<Range<C>> asRanges = ImmutableList.copyOf(rangeSet.asRanges());

    // test that connected ranges are coalesced

  /** Support for {@link Iterator#remove()}. */
  SUPPORTS_REMOVE,
  /**
   * Support for {@link ListIterator#add(Object)}; ignored for plain {@link Iterator}
   * implementations.
   */
  SUPPORTS_ADD,
  /**
   * Support for {@link ListIterator#set(Object)}; ignored for plain {@link Iterator}
   * implementations.
   */
  SUPPORTS_SET;

  /**

   *
   * @return an iterator over the elements in this queue in proper sequence
   */
  @CanIgnoreReturnValue
  @Override
  public Iterator<E> iterator() {
    Monitor monitor = this.monitor;
    monitor.enter();
    try {
      return new Itr();
    } finally {
      monitor.leave();
    }
  }

  /** Iterator for MonitorBasedArrayBlockingQueue */
  private class Itr implements Iterator<E> {

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Iterator;
import org.jspecify.annotations.Nullable;

/**
 * An iterator which forwards all its method calls to another 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>.
 *

    TreeMultimap<String, Integer> multimap = createPopulate();
    Iterator<Entry<String, Collection<Integer>>> iterator = multimap.asMap().entrySet().iterator();
    Entry<String, Collection<Integer>> entry = iterator.next();
    assertEquals("foo", entry.getKey());
    assertThat(entry.getValue()).containsExactly(1, 3, 7);
    entry = iterator.next();
    assertEquals("google", entry.getKey());

  Iterator<N> successorIterator = ImmutableSet.<N>of().iterator();

  static <N> EndpointPairIterator<N> of(BaseGraph<N> graph) {
    return graph.isDirected() ? new Directed<N>(graph) : new Undirected<N>(graph);
  }

  private EndpointPairIterator(BaseGraph<N> graph) {
    this.graph = graph;
    this.nodeIterator = graph.nodes().iterator();
  }

  /**