@SuppressWarnings({"unchecked", "rawtypes"})
                  public Map<Class<?>, Impl> create(Object... elements) {
                    MutableClassToInstanceMap<Impl> map = MutableClassToInstanceMap.create();
                    for (Object object : elements) {
                      Entry<?, ?> entry = (Entry<?, ?>) object;
                      map.putInstance((Class) entry.getKey(), (Impl) entry.getValue());
                    }

     */
    public static void addInterface(final String name, final String syntax) {
        INTERFACES.put(name, syntax);
    }

    private final String proto;
    private Map<String, Object> options = null;
    private final String server;
    private String endpoint = null;
    private UUID uuid = null;
    private int major;
    private int minor;

                        ],
                        "title": "Item",
                        "type": "object",
                    },
                    "ValidationError": {
                        "title": "ValidationError",
                        "required": ["loc", "msg", "type"],
                        "type": "object",
                        "properties": {
                            "loc": {

        return list;
    }

    /**
     * Parses object values from JSON parser.
     *
     * @param jsonParser the JSON parser
     * @return the parsed object as a map
     * @throws IOException if an I/O error occurs
     */
    protected Map<String, Object> parseObject(final JsonParser jsonParser) throws IOException {
        final Map<String, Object> nestedMap = new HashMap<>();

    }

    @Override
    public void acceptAllColumnMap(Entity entity, Map<String, ? extends Object> allColumnMap) {
    }

    @Override
    public Map<String, Object> extractPrimaryKeyMap(Entity entity) {
        return null;
    }

    @Override
    public Map<String, Object> extractAllColumnMap(Entity entity) {
        return null;

    }

    @Override
    public void acceptAllColumnMap(Entity entity, Map<String, ? extends Object> allColumnMap) {
    }

    @Override
    public Map<String, Object> extractPrimaryKeyMap(Entity entity) {
        return null;
    }

    @Override
    public Map<String, Object> extractAllColumnMap(Entity entity) {
        return null;

    }

    @Override
    public void acceptAllColumnMap(Entity entity, Map<String, ? extends Object> allColumnMap) {
    }

    @Override
    public Map<String, Object> extractPrimaryKeyMap(Entity entity) {
        return null;
    }

    @Override
    public Map<String, Object> extractAllColumnMap(Entity entity) {
        return null;

          @Override
          public Object getImpl() {
            return future;
          }
        };
      }
    },
    OLD_ABSTRACT_FUTURE {
      @Override
      ExecutionListWrapper newExecutionList() {
        return new ExecutionListWrapper() {
          final OldAbstractFuture<Object> future = new OldAbstractFuture<Object>() {};

          @Override

   * Entries appear in the result {@code ImmutableBiMap} in encounter order.
   *
   * <p>If the mapped keys or values contain duplicates (according to {@link
   * Object#equals(Object)}), an {@code IllegalArgumentException} is thrown when the collection
   * operation is performed. (This differs from the {@code Collector} returned by {@link

  }

  public void testToOptionalSingleton() {
    assertThat(Stream.of(1).collect(toOptional())).hasValue(1);
  }

  public void testToOptionalNull() {
    Stream<@Nullable Object> stream = Stream.of((Object) null);
    assertThrows(NullPointerException.class, () -> stream.collect(toOptional()));
  }

  public void testToOptionalMultiple() {
    IllegalArgumentException expected =