import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@link AbstractMultiset}.
 *
 * @author Kevin Bourrillion
 * @author Louis Wasserman
 */
@SuppressWarnings("serial") // No serialization is used in this test
@GwtCompatible
@NullMarked

FIELD com.google.common.collect.AbstractMultimap.values com.google.common.collect.Multimaps.MapMultimap.get.$
FIELD com.google.common.collect.AbstractMultiset.entrySet com.google.common.collect.FilteredEntryMultimap.Keys.entrySet.$
FIELD com.google.common.collect.ConcurrentHashMultiset.countMap
FIELD com.google.common.collect.ImmutableMultiset.asList

 * #elementSet()}. Override those methods for better performance.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
abstract class AbstractSortedMultiset<E extends @Nullable Object> extends AbstractMultiset<E>
    implements SortedMultiset<E> {
  private final Comparator<? super E> comparator;

  // needed for serialization
  @SuppressWarnings("unchecked")
  AbstractSortedMultiset() {

 * #elementSet()}. Override those methods for better performance.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
abstract class AbstractSortedMultiset<E extends @Nullable Object> extends AbstractMultiset<E>
    implements SortedMultiset<E> {
  private final Comparator<? super E> comparator;

  // needed for serialization
  @SuppressWarnings("unchecked")
  AbstractSortedMultiset() {

 * @since 2.0
 */
@GwtCompatible
@J2ktIncompatible
@SuppressWarnings("EnumOrdinal") // This is one of the low-level utilities where it's suitable.
public final class EnumMultiset<E extends Enum<E>> extends AbstractMultiset<E>
    implements Serializable {
  /** Creates an empty {@code EnumMultiset}. */
  public static <E extends Enum<E>> EnumMultiset<E> create(Class<E> type) {
    return new EnumMultiset<>(type);
  }

  /**

    successor(b, c);
  }

  /*
   * TODO(jlevy): Decide whether entrySet() should return entries with an equals() method that
   * calls the comparator to compare the two keys. If that change is made,
   * AbstractMultiset.equals() can simply check whether two multisets have equal entry sets.
   */

  /**
   * @serialData the comparator, the number of distinct elements, the first element, its count, the

      builder.put(keyFunction.apply(value), value);
    }
    return builder.build();
  }

  static class Keys<K extends @Nullable Object, V extends @Nullable Object>
      extends AbstractMultiset<K> {
    @Weak final Multimap<K, V> multimap;

    Keys(Multimap<K, V> multimap) {
      this.multimap = multimap;
    }

    @Override
    Iterator<Multiset.Entry<K>> entryIterator() {

      builder.put(keyFunction.apply(value), value);
    }
    return builder.build();
  }

  static class Keys<K extends @Nullable Object, V extends @Nullable Object>
      extends AbstractMultiset<K> {
    @Weak final Multimap<K, V> multimap;

    Keys(Multimap<K, V> multimap) {
      this.multimap = multimap;
    }

    @Override
    Iterator<Multiset.Entry<K>> entryIterator() {