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) {
    ImmutableMultiset.Builder<T> builder = ImmutableMultiset.builder();

  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) {
    ImmutableMultiset.Builder<T> builder = ImmutableMultiset.builder();

        .testForwarding(
            Multiset.class,
            new Function<Multiset, Multiset>() {
              @Override
              public Multiset apply(Multiset delegate) {
                return wrap(delegate);
              }
            });
  }

  public void testEquals() {
    Multiset<String> set1 = ImmutableMultiset.of("one");
    Multiset<String> set2 = ImmutableMultiset.of("two");

    multiset.add("foo", 2);
    multiset.add("bar");
    assertEquals(3, multiset.size());
    assertEquals(2, multiset.count("foo"));
    assertEquals("[foo x 2, bar]", multiset.toString());
  }

  public void testCreateFromIterable() {
    Multiset<String> multiset = TreeMultiset.create(asList("foo", "bar", "foo"));
    assertEquals(3, multiset.size());
    assertEquals(2, multiset.count("foo"));

import java.util.Iterator;
import java.util.NoSuchElementException;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Basic implementation of {@code Multiset<E>} backed by an instance of {@code
 * ObjectCountHashMap<E>}.
 *
 * <p>For serialization to work, the subclass must specify explicit {@code readObject} and {@code
 * writeObject} methods.
 *
 * @author Kevin Bourrillion

 * supplied by the user of the class. For example, {@code Multiset.Entry.getElement()} returns
 * {@code @ParametricNullness E}, which means:
 *
 * <ul>
 *   <li>{@code getElement} on a {@code Multiset.Entry<@NonNull String>} returns {@code @NonNull
 *       String}.
 *   <li>{@code getElement} on a {@code Multiset.Entry<@Nullable String>} returns {@code @Nullable
 *       String}.
 * </ul>
 *

 * supplied by the user of the class. For example, {@code Multiset.Entry.getElement()} returns
 * {@code @ParametricNullness E}, which means:
 *
 * <ul>
 *   <li>{@code getElement} on a {@code Multiset.Entry<@NonNull String>} returns {@code @NonNull
 *       String}.
 *   <li>{@code getElement} on a {@code Multiset.Entry<@Nullable String>} returns {@code @Nullable
 *       String}.
 * </ul>
 *

    setCountCheckReturnValue(element, count);

    assertEquals(
        "multiset.count() should return the value passed to setCount()",
        count,
        getMultiset().count(element));

    int size = 0;
    for (Multiset.Entry<E> entry : getMultiset().entrySet()) {
      size += entry.getCount();
    }
    assertEquals(
        "multiset.size() should be the sum of the counts of all entries",
        size,

import java.util.SortedSet;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A sorted multiset which forwards all its method calls to another sorted multiset. Subclasses
 * should override one or more methods to modify the behavior of the backing multiset as desired per
 * the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *

    return new Enums();
  }

  @Override
  public Multiset<AnEnum> create(Object... elements) {
    AnEnum[] array = new AnEnum[elements.length];
    int i = 0;
    for (Object e : elements) {
      array[i++] = (AnEnum) e;
    }
    return create(array);
  }

  protected abstract Multiset<AnEnum> create(AnEnum[] elements);

  @Override
  public AnEnum[] createArray(int length) {