assertEquals(3, multimap().size());
    assertEquals(3, multimap().entries().size());
    assertEquals(3, multimap().keys().size());

    assertEquals(1, multimap().keySet().size());
    assertEquals(1, multimap().asMap().size());
  }

    @Override
    Object writeReplace() {
      return super.writeReplace();
    }
  }

  static final class KeySet<K> extends ImmutableSet<K> {
    private final transient ImmutableMap<K, ?> map;
    private final transient ImmutableList<K> list;

    KeySet(ImmutableMap<K, ?> map, ImmutableList<K> list) {
      this.map = map;
      this.list = list;
    }

    @Override

    return asList(
        getPutNullKeyUnsupportedMethod(),
        getPutAllNullKeyUnsupportedMethod(),
        getCreateWithNullKeyUnsupportedMethod(),
        getCreateWithNullUnsupportedMethod(), // for keySet
        getContainsEntryWithIncomparableKeyMethod(),
        getContainsEntryWithIncomparableValueMethod());
  }

  @Override
  protected Collection<Method> suppressForConcurrentHashMap() {
    /*

    return asList(
        getPutNullKeyUnsupportedMethod(),
        getPutAllNullKeyUnsupportedMethod(),
        getCreateWithNullKeyUnsupportedMethod(),
        getCreateWithNullUnsupportedMethod(), // for keySet
        getContainsEntryWithIncomparableKeyMethod(),
        getContainsEntryWithIncomparableValueMethod());
  }

  @Override
  protected Collection<Method> suppressForConcurrentHashMap() {
    /*

 * import static org.codelibs.core.collection.MultiIterator.*;
 *
 * List<String> list = ...;
 * Set<String> set = ...;
 * Map<String, Object> map = ...;
 * for (String element : iterable(list, set, map.keySet())) {
 *     ...
 * }
 * </pre>
 *
 * @author koichik
 * @param <E> the element type
 */
public class MultiIterator<E> implements Iterator<E> {

    /** Array of {@link Iterator}s. */

    Map<String, Integer> map = ImmutableSortedMap.of("one", 1, "two", 2, "three", 3);
    SerializableTester.reserializeAndAssert(map.entrySet());
    SerializableTester.reserializeAndAssert(map.keySet());
    assertEquals(
        new ArrayList<>(map.values()),
        new ArrayList<>(SerializableTester.reserialize(map.values())));
  }

    @SuppressWarnings("unchecked")
    ImmutableList<K> keyList =
        (ImmutableList<K>)
            new RegularImmutableMap.KeysOrValuesAsList(alternatingKeysAndValues, keyOffset, size);
    return new RegularImmutableMap.KeySet<>(this, keyList);
  }

  @Override
  boolean isPartialView() {
    return false;
  }

  // redeclare to help optimizers with b/310253115
  @SuppressWarnings("RedundantOverride")
  @Override

      this.upperBound = upperBound;
      checkArgument(
          lowerBound == null || upperBound == null || compare(lowerBound, upperBound) <= 0);
    }

    @Override
    public SortedSet<C> keySet() {
      return new Maps.SortedKeySet<>(this);
    }

    @Override
    public Comparator<? super C> comparator() {
      return columnComparator();
    }

    int compare(Object a, Object b) {

    }

    @Override
    public Enumeration<Object> keys() {
        return getProperties().keys();
    }

    @Override
    public Set<Object> keySet() {
        return getProperties().keySet();
    }

    @Override
    public void list(final PrintStream out) {
        getProperties().list(out);
    }

    @Override
    public void list(final PrintWriter out) {

              return values().asList().get(index + 1);
            });
    List<Entry<K, V>> orderedEntries = getOrderedElements();
    int index = 0;
    for (K key : getMap().keySet()) {
      assertEquals(orderedEntries.get(index).getKey(), key);
      index++;
    }
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)