final FessConfig fessConfig = createFessConfigWithResponseHeaders("*=X-Def:def\napplication/json=X-Json:jsonval");
        FessActionAdjustmentProvider provider = new FessActionAdjustmentProvider(fessConfig);
        final Map<String, String> headerMap = new HashMap<>();
        provider.adjustActionResponseHeaders("application/json", (k, v) -> headerMap.put(k, v));
        assertEquals(2, headerMap.size());

	NewerThan     time.Duration `yaml:"newerThan,omitempty" json:"newerThan"`
	OlderThan     time.Duration `yaml:"olderThan,omitempty" json:"olderThan"`
	CreatedAfter  time.Time     `yaml:"createdAfter,omitempty" json:"createdAfter"`
	CreatedBefore time.Time     `yaml:"createdBefore,omitempty" json:"createdBefore"`
	Tags          []BatchJobKV  `yaml:"tags,omitempty" json:"tags"`

import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.JsonParser;
import com.google.api.client.json.JsonToken;
import com.google.api.client.json.gson.GsonFactory;
import com.google.common.io.BaseEncoding;
import com.google.common.io.BaseEncoding.DecodingException;

Zum Beispiel deklariert das obige Modell ein JSON "`object`" (oder Python-`dict`) wie dieses:

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

Da `description` und `tax` optional sind (mit `None` als Defaultwert), wäre folgendes JSON "`object`" auch gültig:

```JSON
{
    "name": "Foo",
    "price": 45.2
}
```

import okhttp3.Cache;
import okhttp3.HttpUrl;
import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;

/**
 * Fetches HTML from a requested URL, follows the links, and repeats.
 */
public final class Crawler {
  private final OkHttpClient client;

<div class="screenshot">
<img src="/img/tutorial/separate-openapi-schemas/image02.png">
</div>

Esto significa que **siempre tendrá un valor**, solo que a veces el valor podría ser `None` (o `null` en JSON).

По умолчанию **FastAPI** автоматически преобразует возвращаемое значение в JSON с помощью `jsonable_encoder`, как описано в [JSON кодировщик](../tutorial/encoder.md){.internal-link target=_blank}.

Затем "под капотом" эти данные, совместимые с JSON (например `dict`), помещаются в `JSONResponse`, который используется для отправки ответа клиенту.

    /**
     * Retrieves Kuromoji dictionary settings with pagination support.
     *
     * @param dictId the dictionary ID
     * @param body the search body containing pagination and filter parameters
     * @return JSON response containing list of Kuromoji dictionary items
     */
    // GET /api/admin/dict/kuromoji/settings/{dictId}
    @Execute
    public JsonResponse<ApiResult> get$settings(final String dictId, final SearchBody body) {

    /**
     * Retrieve list of protected words entries for the specified dictionary.
     *
     * @param dictId identifier of the dictionary
     * @param body search criteria and paging parameters
     * @return JSON response containing list of entries
     */
    // GET /api/admin/dict/protwords/settings/{dictId}
    @Execute
    public JsonResponse<ApiResult> get$settings(final String dictId, final SearchBody body) {

    /**
     * Retrieves web configuration settings with pagination.
     *
     * @param body the search parameters for filtering and pagination
     * @return JSON response containing web configuration settings list
     */
    // GET /api/admin/webconfig/settings
    // PUT /api/admin/webconfig/settings
    @Execute
    public JsonResponse<ApiResult> settings(final SearchBody body) {