Entry<String, String> firstEntry = entries.iterator().next();
    entries.remove(firstEntry);
    assertFalse(underlying.containsKey("f"));

    Iterator<Entry<String, String>> entryIterator = entries.iterator();
    entryIterator.next();
    entryIterator.remove();
    assertFalse(underlying.containsKey("g"));

    assertTrue(underlying.isEmpty());
    assertTrue(map.isEmpty());
    assertTrue(keys.isEmpty());

import java.util.NavigableSet;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * A skeleton implementation of a descending multiset. Only needs {@code forwardMultiset()} and
 * {@code entryIterator()}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
abstract class DescendingMultiset<E extends @Nullable Object> extends ForwardingMultiset<E>
    implements SortedMultiset<E> {

    return Iterators.<@Nullable Entry<K, V>>getNext(entryIterator(), null);
  }

  @Override
  public @Nullable Entry<K, V> lastEntry() {
    return Iterators.<@Nullable Entry<K, V>>getNext(descendingEntryIterator(), null);
  }

  @Override
  public @Nullable Entry<K, V> pollFirstEntry() {
    return Iterators.pollNext(entryIterator());
  }

  @Override
  public @Nullable Entry<K, V> pollLastEntry() {

    Iterator<Entry<String, Integer>> entryIterator = multimap.entries().iterator();
    assertEquals(immutableEntry("foo", 5), entryIterator.next());
    assertEquals(immutableEntry("bar", 4), entryIterator.next());
    assertEquals(immutableEntry("foo", 3), entryIterator.next());
    assertEquals(immutableEntry("cow", 2), entryIterator.next());
    assertEquals(immutableEntry("bar", 1), entryIterator.next());

import java.util.Set;
import java.util.SortedSet;
import org.jspecify.annotations.Nullable;

/**
 * A skeleton implementation of a descending multiset. Only needs {@code forwardMultiset()} and
 * {@code entryIterator()}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
abstract class DescendingMultiset<E extends @Nullable Object> extends ForwardingMultiset<E>
    implements SortedMultiset<E> {

import java.util.NavigableSet;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * A skeleton implementation of a descending multiset. Only needs {@code forwardMultiset()} and
 * {@code entryIterator()}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
abstract class DescendingMultiset<E extends @Nullable Object> extends ForwardingMultiset<E>
    implements SortedMultiset<E> {

    return Iterators.<@Nullable Entry<K, V>>getNext(entryIterator(), null);
  }

  @Override
  public @Nullable Entry<K, V> lastEntry() {
    return Iterators.<@Nullable Entry<K, V>>getNext(descendingEntryIterator(), null);
  }

  @Override
  public @Nullable Entry<K, V> pollFirstEntry() {
    return Iterators.pollNext(entryIterator());
  }

  @Override
  public @Nullable Entry<K, V> pollLastEntry() {

   */
  protected @Nullable V standardRemove(@Nullable Object key) {
    Iterator<Entry<K, V>> entryIterator = entrySet().iterator();
    while (entryIterator.hasNext()) {
      Entry<K, V> entry = entryIterator.next();
      if (Objects.equals(entry.getKey(), key)) {
        V value = entry.getValue();
        entryIterator.remove();
        return value;
      }
    }
    return null;
  }

  /**

   */
  protected @Nullable V standardRemove(@Nullable Object key) {
    Iterator<Entry<K, V>> entryIterator = entrySet().iterator();
    while (entryIterator.hasNext()) {
      Entry<K, V> entry = entryIterator.next();
      if (Objects.equals(entry.getKey(), key)) {
        V value = entry.getValue();
        entryIterator.remove();
        return value;
      }
    }
    return null;
  }

  /**

    Entry<String, String> firstEntry = entries.iterator().next();
    entries.remove(firstEntry);
    assertFalse(underlying.containsKey("f"));

    Iterator<Entry<String, String>> entryIterator = entries.iterator();
    entryIterator.next();
    entryIterator.remove();
    assertFalse(underlying.containsKey("g"));

    assertTrue(underlying.isEmpty());
    assertTrue(map.isEmpty());
    assertTrue(keys.isEmpty());