var id = lastId
    var type: String? = null
    val data = Buffer()

    while (true) {
      when (source.select(options)) {
        in 0..2 -> {
          completeEvent(id, type, data)
          return true
        }

        in 3..4 -> {
          source.readData(data)
        }

        in 5..7 -> {
          data.writeByte('\n'.code) // 'data' on a line of its own.
        }

        in 8..9 -> {

    assertEquals(written, counter.getCount());

    byte[] data = new byte[10];
    counter.write(data);
    written += 10;
    assertEquals(written, out.size());
    assertEquals(written, counter.getCount());

    counter.write(data, 0, 5);
    written += 5;
    assertEquals(written, out.size());
    assertEquals(written, counter.getCount());

    counter.write(data, 2, 5);
    written += 5;

	// Create a split function that delivers a little data, then a predictable error.
	numSplits := 0
	const okCount = 7
	errorSplit := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
		if atEOF {
			panic("didn't get enough data")
		}
		if numSplits >= okCount {
			return 0, nil, testError
		}
		numSplits++
		return 1, data[0:1], nil
	}
	// Read the data.
	const text = "abcdefghijklmnopqrstuvwxyz"

     * @param key The key to use associate the data with, must not be {@code null}.
     * @param data The data to store in the cache, may be {@code null}.
     */
    void put(RepositoryRequest request, Object key, Object data);

    /**
     * Gets the specified data from the cache. <strong>Warning:</strong> The cache will directly return the saved

          export VAULT_TOKEN
          export data=$(vault read -format=json aws-test/creds/elasticsearch-ci-s3)
          export amazon_s3_access_key=$(echo $data | jq -r .data.access_key)
          export amazon_s3_secret_key=$(echo $data | jq -r .data.secret_key)
          unset VAULT_TOKEN data
          set -x

如果你查看 `/docs`，會看到欄位 `data` 需要 base64 編碼的位元組：

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

你可以發送如下的請求：

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

/// tip

`aGVsbG8=` 是 `hello` 的 base64 編碼。

///

接著 Pydantic 會將該 base64 字串解碼，並在模型的 `data` 欄位中提供原始位元組。

你會收到類似以下的回應：

```json
{

// and options for generating data keys.
type GenerateKeyRequest struct {
	// Name is the name of the master key used to generate
	// the data key.
	Name string

	// AssociatedData is optional data that is cryptographically
	// associated with the generated data key. The same data
	// must be provided when decrypting an encrypted data key.
	//
	// Typically, associated data is some metadata about the

 * This factory maintains a registry of data store implementations and provides methods
 * to register, retrieve, and discover available data stores.
 *
 * <p>Data stores are registered by name and class name, allowing flexible lookup.
 * The factory also supports dynamic discovery of data store plugins by scanning
 * JAR files for data store configurations.</p>
 *

            searchPaging(data, form);
        });
    }

    /**
     * Sets up search paging data for rendering the request header list.
     *
     * @param data the render data to populate
     * @param form the search form containing current search criteria
     */
    protected void searchPaging(final RenderData data, final SearchForm form) {

            searchPaging(data, form);
        });
    }

    /**
     * Sets up data for search result pagination.
     *
     * @param data the render data
     * @param form the search form
     */
    protected void searchPaging(final RenderData data, final SearchForm form) {
        RenderDataUtil.register(data, "fileAuthenticationItems",