}

    /**
     * Creates a client filtered with additional headers.
     *
     * @param headers the headers to add to requests
     * @return the filtered client
     */
    @Override
    public Client filterWithHeader(final Map<String, String> headers) {
        return client.filterWithHeader(headers);
    }

    /**
     * Executes an action asynchronously.
     *

	// handler for validating incoming authorization headers.
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		tc, ok := r.Context().Value(mcontext.ContextTraceKey).(*mcontext.TraceCtxt)

		aType := getRequestAuthType(r)
		switch aType {
		case authTypeSigned, authTypeSignedV2, authTypeStreamingSigned, authTypeStreamingSignedTrailer:
			// Verify if date headers are set, if not reject the request

				t.Errorf("Test %d: Parsed Signature field mismatch: Expected \"%s\", got \"%s\"", i+1, testCase.expectedAuthField.Signature, parsedAuthField.Signature)
			}

			// validating the extracted signed headers.
			if strings.Join(testCase.expectedAuthField.SignedHeaders, ",") != strings.Join(parsedAuthField.SignedHeaders, ",") {

    assertThat(response.body.string()).isEqualTo("a")
    assertThat(eventRecorder.recordedEventTypes())
      .containsExactly(CallStart::class, CallEnd::class)
  }

  /** Response headers start, then the entire request body, then response headers end.  */
  @Test
  fun expectContinueStartsResponseHeadersEarly() {
    server.enqueue(
      MockResponse
        .Builder()
        .add100Continue()
        .build(),

                            .stream()
                            .collect(Collectors.groupingBy(Pair::getFirst, Collectors.mapping(Pair::getSecond, Collectors.toList())));
                    appendJson("headers", requestHeaderMap, buf);
                    buf.append('}');
                    buf.append('\n');
                    try {
                        writer.write(buf.toString());

            responseData.setLastModified(statObject.lastModified() == null ? null : Date.from(statObject.lastModified().toInstant()));
            responseData.setMimeType(statObject.contentType());
            statObject.headers().forEach(e -> responseData.addMetaData(e.getFirst(), e.getSecond()));

            if (contentLengthHelper != null) {
                final long maxLength = contentLengthHelper.getMaxLength(responseData.getMimeType());

    save_data: bool
    if_modified_since: str | None = None
    traceparent: str | None = None
    x_tag: list[str] = []


@app.get("/items/")
async def read_items(headers: Annotated[CommonHeaders, Header()]):
    return headers
```

Read the new docs: [Header Parameter Models](https://fastapi.tiangolo.com/tutorial/header-param-models/).

#### `Cookie` Parameter Models

    * <abbr title="en anglais : path parameters">les paramètres du chemin</abbr>.
    * <abbr title="en anglais : query parameters">les paramètres de la requête</abbr>.
    * les cookies.
    * <abbr title="en anglais : headers">les en-têtes</abbr>.
    * <abbr title="en anglais : forms">les formulaires</abbr>.
    * <abbr title="en anglais : files">les fichiers</abbr>.

    * JSON.
    * Parámetros de path.
    * Parámetros de query.
    * Cookies.
    * Headers.
    * Forms.
    * Archivos.
* <abbr title="también conocido como: serialización, parsing, marshalling">Conversión</abbr> de datos de salida: convirtiendo de datos y tipos de Python a datos de red (como JSON):

* **Editor support**.
* **Type checks**.

...and **FastAPI** uses the same declarations to:

* **Define requirements**: from request path parameters, query parameters, headers, bodies, dependencies, etc.
* **Convert data**: from the request to the required type.
* **Validate data**: coming from each request:
    * Generating **automatic errors** returned to the client when the data is invalid.