* for the data format.
   */
  static <K extends @Nullable Object, V extends @Nullable Object> void populateMap(
      Map<K, V> map, ObjectInputStream stream, int size)
      throws IOException, ClassNotFoundException {
    for (int i = 0; i < size; i++) {
      @SuppressWarnings("unchecked") // reading data stored by writeMap
      K key = (K) stream.readObject();

                System.arraycopy(name, 0, dst, offset, name.length);
                offset += name.length;
            }

            // Write data if present
            if (data != null && data.length > 0) {
                System.arraycopy(data, 0, dst, offset, data.length);
                offset += data.length;
            }

            // Pad to 8-byte boundary
            while ((offset - dstIndex) % 8 != 0) {

 *               operations. May be null for top-level requests.
 * @param data Additional data associated with this request trace, typically containing the actual request
 *             object being processed or any application-specific state information. May be null if no
 *             additional data is needed.
 */
public record RequestTrace(
        @Nullable String context,

///

## About "Form Fields" { #about-form-fields }

The way HTML forms (`<form></form>`) sends the data to the server normally uses a "special" encoding for that data, it's different from JSON.

**FastAPI** will make sure to read that data from the right place instead of JSON.

/// note | Technical Details

Data from forms is normally encoded using the "media type" `application/x-www-form-urlencoded`.

# Versions to use.
CODE=2025c
DATA=2025c

set -e

cd $(dirname $0)
rm -rf work
mkdir work
go build -o work/mkzip mkzip.go # build now for correct paths in build errors
cd work
mkdir zoneinfo
curl -sS -L -O https://www.iana.org/time-zones/repository/releases/tzcode$CODE.tar.gz
curl -sS -L -O https://www.iana.org/time-zones/repository/releases/tzdata$DATA.tar.gz
tar xzf tzcode$CODE.tar.gz

And of course, it supports the same:

* data validation
* data serialization
* data documentation, etc.

This works the same way as with Pydantic models. And it is actually achieved in the same way underneath, using Pydantic.

/// info

								<li class="nav-item" data-bs-toggle="tooltip" data-placement="left" title="<la:message key="labels.eol_error" />">
									<a class="nav-link active" href="${eolLink}" target="_olh"><i class="fas fa-times-circle text-danger" aria-hidden="true"></i></a>
								</li>
							</c:if>
							<c:if test="${developmentMode}">
								<li class="nav-item" data-bs-toggle="tooltip" data-placement="left"

{* ../../docs_src/json_base64_bytes/tutorial001_py310.py ln[1:9,29:35] hl[9] *}

`/docs`를 확인하면 `data` 필드가 base64로 인코딩된 bytes를 기대한다고 표시됩니다:

<div class="screenshot">
<img src="/img/tutorial/json-base64-bytes/image01.png">
</div>

아래와 같은 요청을 보낼 수 있습니다:

```json
{
    "description": "Some data",
    "data": "aGVsbG8="
}
```

/// tip | 팁

`aGVsbG8=`는 `hello`의 base64 인코딩입니다.

///

        byte[] data = "test content".getBytes();
        ContentCache cache = new ContentCache(data);
        response.setContentCache(cache);

        try (InputStream stream = response.getContentAsStream()) {
            assertNotNull(stream);
            byte[] buffer = new byte[1024];
            int bytesRead = stream.read(buffer);
            assertEquals(data.length, bytesRead);

   * (byte[]) data.
   */
  T getExpected(T data);

  /** Cleans up anything created when creating the source or sink. */
  void tearDown() throws IOException;

  /** Factory for byte or char sources. */
  interface SourceFactory<S, T> extends SourceSinkFactory<S, T> {

    /** Creates a new source containing some or all of the given data. */
    S createSource(T data) throws IOException;
  }