assertThat(request.header("Host")).isNull()
    assertThat(request.header("Accept-Encoding")).isNull()

    // No extra headers in the application's response.
    val response = client.newCall(request).execute()
    assertThat(request.header("Content-Encoding")).isNull()
    assertThat(response.body.string()).isEqualTo("abcabcabc")
  }

  @Test
  fun networkInterceptorsCanChangeRequestMethodFromGetToPost() {

    server.enqueue(
      MockResponse(
        headers =
          headersOf(
            "Last-Modified",
            formatDate(-1, TimeUnit.HOURS)!!,
            "Expires",
            formatDate(1, TimeUnit.HOURS)!!,
          ),
        body = "ABC.1",
      ),
    )
    server.enqueue(
      MockResponse(
        headers =
          headersOf(
            "Last-Modified",

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.squareup.okhttp3.maventest;

import java.io.IOException;

import okhttp3.Headers;
import okhttp3.HttpUrl;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class SampleHttpClient {
  private final OkHttpClient client;

  public SampleHttpClient() {

import assertk.assertions.isTrue
import kotlin.test.assertFailsWith
import mockwebserver3.MockResponse
import mockwebserver3.MockWebServer
import mockwebserver3.junit5.StartStop
import okhttp3.Headers.Companion.headersOf
import okhttp3.OkHttpClientTestRule
import okhttp3.Protocol
import okhttp3.RecordingEventListener
import okhttp3.RecordingHostnameVerifier
import okhttp3.Request

      logger.info(String.format("Sending request %s on %s%n%s",
          request.url(), chain.connection(), request.headers()));
      Response response = chain.proceed(request);

      long t2 = System.nanoTime();
      logger.info(String.format("Received response for %s in %.1fms%n%s",
          request.url(), (t2 - t1) / 1e6d, response.headers()));
      return response;
    }
  }

  public static void main(String... args) throws Exception {

Para esos casos, puedes usar un parámetro `Response`.

## Usa un parámetro `Response`

Puedes declarar un parámetro de tipo `Response` en tu *función de path operation* (como puedes hacer para cookies y headers).

Y luego puedes establecer el `status_code` en ese objeto de response *temporal*.

{* ../../docs_src/response_change_status_code/tutorial001.py hl[1,9,12] *}

    }

    /**
     * Processes the CORS request by adding standard CORS headers to the response.
     * Headers include allowed origin, methods, headers, max age, and credentials setting.
     *
     * @param origin the origin of the request
     * @param request the servlet request
     * @param response the servlet response to add CORS headers to
     */
    @Override

/// note | Detalhes Técnicos

`Header` é uma classe "irmã" de `Path`, `Query` e `Cookie`. Ela também herda da mesma classe em comum `Param`.

Mas lembre-se que quando você importa `Query`, `Path`, `Header`, e outras de `fastapi`, elas são na verdade funções que retornam classes especiais.

///

/// info

{* ../../docs_src/header_param_models/tutorial001_an_py310.py hl[9:14,18] *}

O **FastAPI** irá **extrair** os dados de **cada campo** a partir dos **cabeçalhos** da requisição e te retornará o modelo do Pydantic que você definiu.

### Checando a documentação

Você pode ver os headers necessários na interface gráfica da documentação em `/docs`:

But for security, as the server doesn't know it is behind a trusted proxy, it won't interpret those headers.

/// note | Technical Details

The proxy headers are:

* <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-For" class="external-link" target="_blank">X-Forwarded-For</a>