)
    call1.execute().use { response -> response.body.string() }

    listener.shouldClose = true
    // Large headers are a likely reason the servers would cut off the connection before it completes sending
    // request headers.
    // 431 "Request Header Fields Too Large"
    val largeHeaders =
      Headers
        .Builder()
        .apply {
          repeat(32) {
            add("name-$it", "value-$it-" + "0".repeat(1024))

    /**
     * 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()

      System.out.println(response.request().header("Date"));
    }
  }

  static class CurrentDateInterceptor implements Interceptor {
    @Override public Response intercept(Chain chain) throws IOException {
      Request request = chain.request();
      Headers newHeaders = request.headers()
          .newBuilder()
          .add("Date", new Date())
          .build();

 *  Fix: Include a backwards-compatible `OkHttp-Response-Source` header with
    `OkUrlFactory `responses.
 *  Fix: Don't include a default User-Agent header in requests made with the Call
    API. Requests made with OkUrlFactory will continue to have a default user
    agent.
 *  New: Guava-like API to create headers:

    ```java
    Headers headers = Headers.of(name1, value1, name2, value2, ...).
    ```

class APIKeyHeader(APIKeyBase):
    """
    API key authentication using a header.

    This defines the name of the header that should be provided in the request with
    the API key and integrates that into the OpenAPI documentation. It extracts
    the key value sent in the header automatically and provides it as the dependency
    result. But it doesn't define how to send that key to the client.

                                "in": "header",
                                "required": True,
                                "schema": {"type": "string", "title": "Host"},
                            },
                            {
                                "name": "save_data",
                                "in": "header",
                                "required": True,

      transparentGzip = true
      requestBuilder.header("Accept-Encoding", "gzip")
    }

    val cookies = cookieJar.loadForRequest(userRequest.url)
    if (cookies.isNotEmpty()) {
      requestBuilder.header("Cookie", cookieHeader(cookies))
    }

    if (userRequest.header("User-Agent") == null) {
      requestBuilder.header("User-Agent", USER_AGENT)
    }

     */
    @JvmField
    val FORCE_CACHE = commonForceCache()

    /**
     * Returns the cache directives of [headers]. This honors both Cache-Control and Pragma headers
     * if they are present.
     */
    @JvmStatic
    fun parse(headers: Headers): CacheControl = commonParse(headers)
  }

### CORS-Preflight-Requests { #cors-preflight-requests }

Dies sind alle `OPTIONS`-Requests mit `Origin`- und `Access-Control-Request-Method`-Headern.

In diesem Fall wird die Middleware den eingehenden Request abfangen und mit entsprechenden CORS-Headern, und entweder einer `200`- oder `400`-<abbr title="Response – Antwort: Daten, die der Server zum anfragenden Client zurücksendet">Response</abbr> zu Informationszwecken antworten.

def test_read_nonexistent_item():
    response = client.get("/items/baz", headers={"X-Token": "coneofsilence"})
    assert response.status_code == 404
    assert response.json() == {"detail": "Item not found"}


def test_create_item():
    response = client.post(
        "/items/",
        headers={"X-Token": "coneofsilence"},