/**
   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableBiMap} whose keys
   * and values are the result of applying the provided mapping functions to the input elements.
   * Entries appear in the result {@code ImmutableBiMap} in encounter order.
   *
   * <p>If the mapped keys or values contain duplicates (according to {@link

  /**
   * Computes or retrieves the values corresponding to {@code keys}. This method is called by {@link
   * LoadingCache#getAll}.
   *
   * <p>If the returned map doesn't contain all requested {@code keys} then the entries it does
   * contain will be cached, but {@code getAll} will throw an exception. If the returned map
   * contains extra keys not present in {@code keys} then all returned entries will be cached, but

                        keys ->
                            path.create(
                                Lists.transform(
                                    keys, key -> Maps.immutableEntry(key, new Object()))),
                        keys ->
                            path.create(
                                Lists.transform(
                                    keys, key -> Maps.immutableEntry(new Object(), key))),

        .withFeatures(
            MapFeature.GENERAL_PURPOSE,
            MapFeature.ALLOWS_NULL_KEYS,
            MapFeature.ALLOWS_NULL_VALUES,
            MapFeature.ALLOWS_ANY_NULL_QUERIES,
            MapFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION,
            MapFeature.RESTRICTS_KEYS,
            MapFeature.RESTRICTS_VALUES,
            CollectionFeature.SUPPORTS_ITERATOR_REMOVE,

    };
  }

  /**
   * Returns an immutable multiset containing all the keys in this multimap, in the same order and
   * with the same frequencies as they appear in this multimap; to get only a single occurrence of
   * each key, use {@link #keySet}.
   */
  @Override
  public ImmutableMultiset<K> keys() {
    return (ImmutableMultiset<K>) super.keys();
  }

  @Override
  ImmutableMultiset<K> createKeys() {

    }
    expectUnchanged();
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_KEYS})
  public void testPut_nullKeySupportedNotPresent() {
    assertNull("put(null, value) should return null", put(nullKeyEntry));
    expectAdded(nullKeyEntry);
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_KEYS})
  @CollectionSize.Require(absent = ZERO)
  public void testPut_nullKeySupportedPresent() {

        }
      }
      return new ValuesImpl();
    }
  }

  @Override
  Multiset<K> createKeys() {
    return new Keys();
  }

  @WeakOuter
  class Keys extends Multimaps.Keys<K, V> {
    Keys() {
      super(FilteredEntryMultimap.this);
    }

    @Override
    public int remove(@CheckForNull Object key, int occurrences) {

  }

  /**
   * Returns an immutable multiset containing all the keys in this multimap, in the same order and
   * with the same frequencies as they appear in this multimap; to get only a single occurrence of
   * each key, use {@link #keySet}.
   */
  @Override
  public ImmutableMultiset<K> keys() {
    return (ImmutableMultiset<K>) super.keys();
  }

  @Override
  ImmutableMultiset<K> createKeys() {

   * Constructs an empty {@code HashMultimap} with enough capacity to hold the specified numbers of
   * keys and values without rehashing.
   *
   * <p>This method will soon be deprecated in favor of {@code
   * MultimapBuilder.hashKeys(expectedKeys).hashSetValues(expectedValuesPerKey).build()}.
   *
   * @param expectedKeys the expected number of distinct keys
   * @param expectedValuesPerKey the expected average number of values per key

  RESTRICTS_KEYS,
  RESTRICTS_VALUES,
  SUPPORTS_PUT,
  SUPPORTS_REMOVE,
  FAILS_FAST_ON_CONCURRENT_MODIFICATION,
  /**
   * Indicates that the constructor or factory method of a map, usually an immutable map, throws an
   * {@link IllegalArgumentException} when presented with duplicate keys instead of discarding all
   * but one.
   */
  REJECTS_DUPLICATES_AT_CREATION,