*
 * <p>This implementation is heavily derived from revision 1.96 of <a
 * href="http://tinyurl.com/ConcurrentHashMap">ConcurrentHashMap.java</a>.
 *
 * @param <K> the type of the keys in the map
 * @param <V> the type of the values in the map
 * @param <E> the type of the {@link InternalEntry} entry implementation used internally
 * @param <S> the type of the {@link Segment} entry implementation used internally

    map.remove("a");
    assertFalse(underlying.containsKey("a"));

    Set<String> keys = map.keySet();
    keys.remove("b");
    assertFalse(underlying.containsKey("b"));

    Iterator<String> keyIterator = keys.iterator();
    keyIterator.next();
    keyIterator.remove();
    assertFalse(underlying.containsKey("c"));

      throw new UncheckedExecutionException(e.getCause());
    }
  }

  @Override
  public ImmutableMap<K, V> getAll(Iterable<? extends K> keys) throws ExecutionException {
    Map<K, V> result = Maps.newLinkedHashMap();
    for (K key : keys) {
      if (!result.containsKey(key)) {
        result.put(key, get(key));
      }
    }
    return ImmutableMap.copyOf(result);
  }

  @Override

      throw new UncheckedExecutionException(e.getCause());
    }
  }

  @Override
  public ImmutableMap<K, V> getAll(Iterable<? extends K> keys) throws ExecutionException {
    Map<K, V> result = Maps.newLinkedHashMap();
    for (K key : keys) {
      if (!result.containsKey(key)) {
        result.put(key, get(key));
      }
    }
    return ImmutableMap.copyOf(result);
  }

  @Override

    return delegate().getUnchecked(key);
  }

  @CanIgnoreReturnValue // TODO(b/27479612): consider removing this
  @Override
  public ImmutableMap<K, V> getAll(Iterable<? extends K> keys) throws ExecutionException {
    return delegate().getAll(keys);
  }

  @Override
  public V apply(K key) {
    return delegate().apply(key);
  }

  @Override
  public void refresh(K key) {
    delegate().refresh(key);
  }

      assertTrue(multimap().asMap().get(key) instanceof Set);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testAsMapRemoveImplementsSet() {
    List<K> keys = new ArrayList<>(multimap().keySet());
    for (K key : keys) {
      resetCollection();
      assertTrue(multimap().asMap().remove(key) instanceof Set);
    }
  }

  @CollectionSize.Require(SEVERAL)
  public void testEquals() {

            .named("Synchronized.biMap[TestBiMap]")
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.SUPPORTS_ITERATOR_REMOVE,
                MapFeature.ALLOWS_NULL_KEYS,
                MapFeature.ALLOWS_NULL_VALUES,
                MapFeature.ALLOWS_ANY_NULL_QUERIES,
                MapFeature.GENERAL_PURPOSE,
                MapFeature.REJECTS_DUPLICATES_AT_CREATION)

import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEY_QUERIES;
import static com.google.common.collect.testing.features.MapFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION;

import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEY_QUERIES;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_VALUES;

      for (K element : insertionOrder) {
        entries.add(mapEntry(element, v));
      }

      List<K> keys = new ArrayList<>();
      for (Entry<K, V> entry : mapGenerator.order(entries)) {
        keys.add(entry.getKey());
      }
      return keys;
    }

    @Override
    public OneSizeTestContainerGenerator<Map<K, V>, Entry<K, V>> getInnerGenerator() {
      return mapGenerator;