}

  /** All the ways to create an ImmutableMultiset. */
  enum ConstructionPathway implements Construction<Multiset<Object>> {
    COPY_OF_COLLECTION {
      @Override
      public ImmutableMultiset<Object> create(List<?> keys) {
        return ImmutableMultiset.copyOf(keys);
      }
    },
    COPY_OF_ITERATOR {
      @Override
      public ImmutableMultiset<Object> create(List<?> keys) {

      }
    };
  }

  private static <T> ImmutableMultiset<T> multiset(T value, int count) {
    return multiset(ImmutableMap.of(value, count));
  }

  private static <T> ImmutableMultiset<T> multiset(T value1, int count1, T value2, int count2) {
    return multiset(ImmutableMap.of(value1, count1, value2, count2));
  }

  private static <T> ImmutableMultiset<T> multiset(Map<T, Integer> counts) {

      }
    };
  }

  private static <T> ImmutableMultiset<T> multiset(T value, int count) {
    return multiset(ImmutableMap.of(value, count));
  }

  private static <T> ImmutableMultiset<T> multiset(T value1, int count1, T value2, int count2) {
    return multiset(ImmutableMap.of(value1, count1, value2, count2));
  }

  private static <T> ImmutableMultiset<T> multiset(Map<T, Integer> counts) {

final class RegularImmutableMultiset<E> extends ImmutableMultiset<E> {
  static final ImmutableMultiset<Object> EMPTY =
      JdkBackedImmutableMultiset.create(ImmutableList.of());

  RegularImmutableMultiset() {}

  static <E> ImmutableMultiset<E> create(Collection<? extends Entry<? extends E>> entries) {
    if (entries.isEmpty()) {
      return ImmutableMultiset.of();
    } else {

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

/**
 * An implementation of ImmutableMultiset backed by a JDK Map and a list of entries. Used to protect
 * against hash flooding attacks.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class JdkBackedImmutableMultiset<E> extends ImmutableMultiset<E> {
  private final Map<E, Integer> delegateMap;
  private final ImmutableList<Entry<E>> entries;

import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableMultiset} with zero or more elements.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class RegularImmutableMultiset<E> extends ImmutableMultiset<E> {
  static final RegularImmutableMultiset<Object> EMPTY =

          multiset2.add(elements[i], i + 1);
        }
        return difference(multiset1, multiset2);
      }
    };
  }

  private static final ImmutableMultiset<String> ELEMENTS_TO_FILTER_OUT =
      ImmutableMultiset.of("foobar", "bazfoo", "foobar", "foobar");

  private static final Predicate<String> PREDICATE = not(Predicates.in(ELEMENTS_TO_FILTER_OUT));

  static <E> Multiset<E> reserializeAndAssertLenient(Multiset<E> original) {
    Multiset<E> copy = reserialize(original);
    assertEquals(original, copy);
    assertTrue(copy instanceof ImmutableMultiset);
    return copy;
  }

  @CanIgnoreReturnValue
  @GwtIncompatible // SerializableTester
  static <E> Collection<E> reserializeAndAssertElementsEqual(Collection<E> original) {

          public int add(String element, int occurrences) {
            addCalls.incrementAndGet();
            return super.add(element, occurrences);
          }
        };
    ImmutableMultiset<String> adds =
        new ImmutableMultiset.Builder<String>().addCopies("x", 10).build();
    multiset.addAll(adds);
    assertEquals(1, addCalls.get());
  }

  public void testRemoveUnsupported() {

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
FIELD com.google.common.collect.ImmutableRangeMap.ranges
FIELD com.google.common.collect.ImmutableRangeSet.ranges
FIELD com.google.common.collect.ImmutableSet.asList