*       instance is unsafely published.
   * </ul>
   */
  private transient @Nullable ConcurrentHashMultiset<E> deserializationReplacement;

  /**
   * Creates a new, empty {@code ConcurrentHashMultiset} using the default initial capacity, load
   * factor, and concurrency settings.
   */
  public static <E> ConcurrentHashMultiset<E> create() {
    return create(new ConcurrentHashMap<>());
  }

  /**

    private final ContainsMultiset a;
    private final ConcurrentHashMultiset<?> z;

    ContainsBothWithContainsMultisetFirst(ContainsMultiset a, ConcurrentHashMultiset<?> z) {
      this.a = a;
      this.z = z;
    }
  }

  public void testCreate() {
    ConcurrentHashMultiset<Integer> multiset = ConcurrentHashMultiset.create();
    assertTrue(multiset.isEmpty());
    reserializeAndAssert(multiset);

package com.google.common.util.concurrent;

import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
import static java.util.concurrent.Executors.newFixedThreadPool;

import com.google.common.collect.ConcurrentHashMultiset;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableMultiset;
import com.google.common.collect.Multiset;
import com.google.common.testing.TestLogHandler;
import java.util.Map;

package com.google.common.util.concurrent;

import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
import static java.util.concurrent.Executors.newFixedThreadPool;

import com.google.common.collect.ConcurrentHashMultiset;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableMultiset;
import com.google.common.collect.Multiset;
import com.google.common.testing.TestLogHandler;
import java.util.Map;

    testAddAndRemove(mapMaker.makeMap());
  }

  private void testAddAndRemove(ConcurrentMap<String, AtomicInteger> map)
      throws ExecutionException, InterruptedException {

    ConcurrentHashMultiset<String> multiset = ConcurrentHashMultiset.create(map);
    int nThreads = 20;
    int tasksPerThread = 10;
    int nTasks = nThreads * tasksPerThread;
    ExecutorService pool = newFixedThreadPool(nThreads);

 *
 * <p><b>Note:</b> If your values are always positive and less than 2^31, you may wish to use a
 * {@link com.google.common.collect.Multiset} such as {@link
 * com.google.common.collect.ConcurrentHashMultiset} instead.
 *
 * <p><b>Warning:</b> Unlike {@code Multiset}, entries whose values are zero are not automatically
 * removed from the map. Instead they must be removed manually with {@link #removeAllZeros}.
 *

      }
    },
    ConcurrentHashMultisetImpl {
      @Override
      public <E extends Comparable<E>> Multiset<E> create(Collection<E> contents) {
        return ConcurrentHashMultiset.create(contents);
      }
    },
    ImmutableMultisetImpl {
      @Override
      public <E extends Comparable<E>> Multiset<E> create(Collection<E> contents) {

 *   <li>{@link ImmutableSortedMultiset}
 *   <li>{@link HashMultiset}
 *   <li>{@link LinkedHashMultiset}
 *   <li>{@link TreeMultiset}
 *   <li>{@link EnumMultiset}
 *   <li>{@link ConcurrentHashMultiset}
 * </ul>
 *
 * <p>If your values may be zero, negative, or outside the range of an int, you may wish to use
 * {@link com.google.common.util.concurrent.AtomicLongMap} instead. Note, however, that unlike

   * is used only by those methods, and it is never set in a "normal" instance.
   *
   * <p>For more background, see {@code ConcurrentHashMultiset.deserializationReplacement}.
   */
  private transient @Nullable TreeMultiset<E> deserializationReplacement;

  TreeMultiset(Reference<AvlNode<E>> rootReference, GeneralRange<E> range, AvlNode<E> endLink) {

 *   <li>{@link ImmutableSortedMultiset}
 *   <li>{@link HashMultiset}
 *   <li>{@link LinkedHashMultiset}
 *   <li>{@link TreeMultiset}
 *   <li>{@link EnumMultiset}
 *   <li>{@link ConcurrentHashMultiset}
 * </ul>
 *
 * <p>If your values may be zero, negative, or outside the range of an int, you may wish to use
 * {@link com.google.common.util.concurrent.AtomicLongMap} instead. Note, however, that unlike