}

  /** 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) {

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

@ElementTypesAreNonnullByDefault
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 {

 * ImmutableMultiset}. The GWT supersource for this class contains a field of type {@code E}.
 *
 * <p>For details about this hack, see {@code GwtSerializationDependencies}, which takes the same
 * approach but with a subclass rather than a superclass.
 *
 * <p>TODO(cpovirk): Consider applying this subclass approach to our other types.
 *

      }
    };
  }

  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) {

  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) {

  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) {

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

          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() {