val connect = server.takeRequest()
    assertThat(connect.headers["Private"]).isNull()
    assertThat(connect.headers["Proxy-Authorization"]).isNull()
    assertThat(connect.headers["User-Agent"]).isEqualTo(USER_AGENT)
    assertThat(connect.headers["Host"]).isEqualTo("android.com:443")
    assertThat(connect.headers["Proxy-Connection"]).isEqualTo("Keep-Alive")
    val get = server.takeRequest()

import com.google.common.collect.testing.testers.MapIsEmptyTester;
import com.google.common.collect.testing.testers.MapPutAllTester;
import com.google.common.collect.testing.testers.MapPutTester;
import com.google.common.collect.testing.testers.MapRemoveTester;
import com.google.common.collect.testing.testers.MapSerializationTester;
import com.google.common.collect.testing.testers.MapSizeTester;

    assert response.status_code == 401, response.text
    assert response.headers["WWW-Authenticate"] == "Basic"


def test_security_http_basic_invalid_credentials(client: TestClient):
    response = client.get(
        "/users/me", headers={"Authorization": "Basic notabase64token"}
    )
    assert response.status_code == 401, response.text
    assert response.headers["WWW-Authenticate"] == "Basic"

  const val FLAG_ACK = 0x1 // Used for settings and ping.
  const val FLAG_END_STREAM = 0x1 // Used for headers and data.
  const val FLAG_END_HEADERS = 0x4 // Used for headers and continuation.
  const val FLAG_END_PUSH_PROMISE = 0x4
  const val FLAG_PADDED = 0x8 // Used for headers and data.
  const val FLAG_PRIORITY = 0x20 // Used for headers.
  const val FLAG_COMPRESSED = 0x20 // Used for data.

  /** Lookup table for valid frame types. */

def test_read_item():
    response = client.get("/items/foo", headers={"X-Token": "coneofsilence"})
    assert response.status_code == 200
    assert response.json() == {
        "id": "foo",
        "title": "Foo",
        "description": "There goes my hero",
    }


def test_read_item_bad_token():
    response = client.get("/items/foo", headers={"X-Token": "hailhydra"})
    assert response.status_code == 400

    /**
     * Returns the subset of the headers in [requestHeaders] that impact the content of the
     * response's body.
     */
    private fun varyHeaders(
      requestHeaders: Headers,
      responseHeaders: Headers,
    ): Headers {
      val varyFields = responseHeaders.varyFields()
      if (varyFields.isEmpty()) return Headers.EMPTY

      val result = Headers.Builder()

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3.internal.http1

import okhttp3.Headers
import okio.BufferedSource

/**
 * Parse all headers delimited by "\r\n" until an empty line. This throws if headers exceed 256 KiB.
 */
class HeadersReader(
  val source: BufferedSource,
) {
  private var headerLimit = HEADER_LIMIT.toLong()

**FastAPI** **extraerá** los datos para **cada campo** de los **headers** en el request y te dará el modelo Pydantic que definiste.

## Revisa la Documentación { #check-the-docs }

Puedes ver los headers requeridos en la interfaz de documentación en `/docs`:

<div class="screenshot">
<img src="/img/tutorial/header-param-models/image01.png">
</div>

## Prohibir Headers Extra { #forbid-extra-headers }

    val authority = request.headers["Host"] // Has host and port.
    val fancyRequest =
      Request
        .Builder()
        .url("$scheme://$authority/")
        .headers(request.headers)
        .build()
    val fancyResponse =
      Response
        .Builder()
        .code(webSocketResponse.code)
        .message(webSocketResponse.message)
        .headers(webSocketResponse.headers)

    assertThat(recorded.headers["Accept"]).isEqualTo("text/plain")
    assertThat(recorded.headers["Accept-Encoding"]).isNull() // No built-in gzip.
    assertThat(recorded.headers["Connection"]).isEqualTo("Upgrade, HTTP2-Settings")
    if (PlatformVersion.majorVersion < 19) {
      assertThat(recorded.headers["Content-Length"]).isEqualTo("0")
    }
    assertThat(recorded.headers["HTTP2-Settings"]).isNotNull()