* created automatically.
     *
     * @param output The file to serialize the model to, must not be {@code null}.
     * @param options The options to use for serialization, may be {@code null} to use the default values.
     * @param model The model to serialize, must not be {@code null}.
     * @throws IOException If the model could not be serialized.
     */

        return ObjectInputFilter.Status.REJECTED;
    };

    /**
     * Tests if the object can be serialized.
     *
     * @param obj the object to be serialized (must not be {@literal null})
     * @return the deserialized object
     */
    public static Object serialize(final Object obj) {
        assertArgumentNotNull("obj", obj);

        final byte[] binary = fromObjectToBinary(obj);

    category=FastAPIDeprecationWarning,
    stacklevel=2,
)
class UJSONResponse(JSONResponse):
    """JSON response using the ujson library to serialize data to JSON.

    **Deprecated**: `UJSONResponse` is deprecated. FastAPI now serializes data
    directly to JSON bytes via Pydantic when a return type or response model is
    set, which is faster and doesn't need a custom response class.

    Read more in the

	// Set WantParts to indicate 3 parts
	finalChecksum.WantParts = 3

	// Test AppendTo serialization
	var serialized []byte
	serialized = finalChecksum.AppendTo(serialized, checksumCombined)

	// Use ChecksumFromBytes to deserialize the final checksum
	chksmOut := ChecksumFromBytes(serialized)
	if chksmOut == nil {
		t.Fatal("ChecksumFromBytes returned nil")
	}

	// Assert they are exactly equal

     * the method returns.
     *
     * @param output The writer to serialize the toolchains to, must not be {@code null}.
     * @param options The options to use for serialization, may be {@code null} to use the default values.
     * @param toolchains The toolchains to serialize, must not be {@code null}.
     * @throws IOException If the toolchains could not be serialized.
     */

   * concurrent maps whose content may change while the method is running.
   *
   * <p>The serialized output consists of the number of entries, first key, first value, second key,
   * second value, and so on.
   */
  static <K extends @Nullable Object, V extends @Nullable Object> void writeMap(
      Map<K, V> map, ObjectOutputStream stream) throws IOException {
    stream.writeInt(map.size());

		if err != nil {
			return keys, err
		}
	}
	return keys, nil
}

// serialize will serialize the provided keys and values.
// The function will panic if keys/value slices aren't of equal length.
// Payload size can give an indication of expected payload size.
// If plSize is <= 0 it will be calculated.
func (x *xlMetaInlineData) serialize(plSize int, keys [][]byte, vals [][]byte) {
	if len(keys) != len(vals) {

   * concurrent maps whose content may change while the method is running.
   *
   * <p>The serialized output consists of the number of entries, first key, first value, second key,
   * second value, and so on.
   */
  static <K extends @Nullable Object, V extends @Nullable Object> void writeMap(
      Map<K, V> map, ObjectOutputStream stream) throws IOException {
    stream.writeInt(map.size());

If you declare the return type as `AsyncIterable[Item]`, FastAPI will use it to **validate**, **document**, and **serialize** the data using Pydantic.

{* ../../docs_src/server_sent_events/tutorial001_py310.py ln[1:25] hl[10:12,23] *}

/// tip

As Pydantic will serialize it in the **Rust** side, you will get much higher **performance** than if you don't declare a return type.

///

If you declare the return type, FastAPI will use it to **validate** the data, **document** it in OpenAPI, **filter** it, and **serialize** it using Pydantic.

/// tip

As Pydantic will serialize it in the **Rust** side, you will get much higher **performance** than if you don't declare a return type.

///