// TODO(lowasser): implement removeEldestEntry so this can be used as a drop-in replacement

  /** Creates an empty {@code CompactLinkedHashMap} instance. */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      CompactLinkedHashMap<K, V> create() {
    return new CompactLinkedHashMap<>();
  }

  /**
   * Creates a {@code CompactLinkedHashMap} instance, with a high enough "initial capacity" that it

  }

  /**
   * Returns a builder that creates immutable sorted sets whose elements are ordered by the reverse
   * of their natural ordering.
   */
  public static <E extends Comparable<?>> Builder<E> reverseOrder() {
    return new Builder<>(Collections.reverseOrder());
  }

  /**
   * Returns a builder that creates immutable sorted sets whose elements are ordered by their

 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class TreeMultiset<E extends @Nullable Object> extends AbstractSortedMultiset<E>
    implements Serializable {

  /**
   * Creates a new, empty multiset, sorted according to the elements' natural order. All elements
   * inserted into the multiset must implement the {@code Comparable} interface. Furthermore, all

   * created multimaps.
   *
   * @since 2.0
   */
  public static final class Builder<K, V> extends ImmutableMultimap.Builder<K, V> {
    /**
     * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
     * ImmutableSetMultimap#builder}.
     */
    public Builder() {
      super();
    }

    @Override

    }
  }

  /**
   * Returns a builder that creates immutable sorted maps whose keys are ordered by their natural
   * ordering. The sorted maps use {@link Ordering#natural()} as the comparator.
   */
  public static <K extends Comparable<?>, V> Builder<K, V> naturalOrder() {
    return new Builder<>(Ordering.natural());
  }

  /**
   * Returns a builder that creates immutable sorted maps with an explicit comparator. If the

   * multiple multisets in series.
   *
   * @since 2.0
   */
  public static class Builder<E> extends ImmutableCollection.Builder<E> {
    final Multiset<E> contents;

    /**
     * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
     * ImmutableMultiset#builder}.
     */
    public Builder() {
      this(LinkedHashMultiset.<E>create());
    }

    // The first `size` elements are non-null.
    @VisibleForTesting @Nullable Object[] contents;
    private int size;
    private boolean forceCopy;

    /**
     * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
     * ImmutableList#builder}.
     */
    public Builder() {
      this(DEFAULT_INITIAL_CAPACITY);
    }

public final class HashMultiset<E extends @Nullable Object> extends AbstractMapBasedMultiset<E> {

  /** Creates a new, empty {@code HashMultiset} using the default initial capacity. */
  public static <E extends @Nullable Object> HashMultiset<E> create() {
    return new HashMultiset<>();
  }

  /**
   * Creates a new, empty {@code HashMultiset} with the specified expected number of distinct
   * elements.
   *

      Iterable<E> iterable, Class<E> elementType) {
    EnumSet<E> set = EnumSet.noneOf(elementType);
    Iterables.addAll(set, iterable);
    return set;
  }

  // HashSet

  /**
   * Creates a <i>mutable</i>, initially empty {@code HashSet} instance.
   *
   * <p><b>Note:</b> if mutability is not required, use {@link ImmutableSet#of()} instead. If {@code

      synchronized (lock) {
        int numRunning = --runningTasks;
        if (numRunning == 0) {
          lock.notifyAll();
        }
      }
    }
  }

  /**
   * Creates an executor service that runs each task in the thread that invokes {@code
   * execute/submit}, as in {@code ThreadPoolExecutor.CallerRunsPolicy}. This applies both to