this.keys = new @Nullable Object[initialCapacity];
      this.values = new @Nullable Object[initialCapacity];
    }

    private void ensureCapacity(int minCapacity) {
      if (minCapacity > keys.length) {
        int newCapacity = ImmutableCollection.Builder.expandedCapacity(keys.length, minCapacity);
        this.keys = Arrays.copyOf(keys, newCapacity);

      super.put(entry);
      return this;
    }

    /**
     * Associates all of the given map's keys and values in the built map. Duplicate keys, according
     * to the comparator (which might be the keys' natural order), are not allowed, and will cause
     * {@link #build} to fail.
     *
     * @throws NullPointerException if any key or value in {@code map} is null
     */
    @CanIgnoreReturnValue
    @Override

 *
 * <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

      return unmodifiableValueCollection(delegate.get(key));
    }

    @Override
    public Multiset<K> keys() {
      Multiset<K> result = keys;
      if (result == null) {
        keys = result = Multisets.unmodifiableMultiset(delegate.keys());
      }
      return result;
    }

    @Override
    public Set<K> keySet() {
      Set<K> result = keySet;

 *
 * <p><b>Note:</b> by default, the returned cache uses equality comparisons (the {@link
 * Object#equals equals} method) to determine equality for keys or values. However, if {@link
 * #weakKeys} was specified, the cache uses identity ({@code ==}) comparisons instead for keys.
 * Likewise, if {@link #weakValues} or {@link #softValues} was specified, the cache uses identity
 * comparisons for values.
 *

            return new Object();
          }

          @Override
          public Map<Object, Object> loadAll(Iterable<?> keys) throws Exception {
            Map<Object, Object> result = Maps.newHashMap();
            for (Object key : keys) {
              Object value = new Object();
              result.put(key, value);
              // add extra entries
              result.put(value, key);

            return new Object();
          }

          @Override
          public Map<Object, Object> loadAll(Iterable<?> keys) throws Exception {
            Map<Object, Object> result = Maps.newHashMap();
            for (Object key : keys) {
              Object value = new Object();
              result.put(key, value);
              // add extra entries
              result.put(value, key);

  /// Returns a list of valid configuration keys in `keys` array and number of
  /// keys in `num_keys`. Ownership of the buffers in `keys` are transferred to
  /// caller and needs to be freed using relevant filesystem allocation API.
  ///
  /// Plugins:
  ///   * Must set `status` to `TF_OK` on success. If there are no configurable
  ///     keys, `num_keys` should be set to 0

        }
        return asMap;
      }
    }

    @Override
    public Multiset<K> keys() {
      synchronized (mutex) {
        if (keys == null) {
          keys = multiset(delegate().keys(), mutex);
        }
        return keys;
      }
    }

    @Override
    public boolean equals(@CheckForNull Object o) {
      if (o == this) {
        return true;

		return err
	}

	// We map keys that correspond to LDAP DNs and validate that they exist in
	// the LDAP server.
	var dnValidator func(*libldap.Conn, string) (string, bool, error) = sys.LDAPConfig.GetValidatedUserDN
	if isGroup {
		dnValidator = sys.LDAPConfig.GetValidatedGroupDN
	}

	// map of normalized DN keys to original keys.
	normalizedDNKeysMap := make(map[string][]string)