}

  @Test
  @Throws(IOException::class)
  fun http1DoesntSupportDuplex() {
    val call =
      client.newCall(
        Request.Builder()
          .url(server.url("/"))
          .post(AsyncRequestBody())
          .build(),
      )
    assertFailsWith<ProtocolException> {
      call.execute()
    }
  }

  @Test
  fun trueDuplexClientWritesFirst() {
    enableProtocol(Protocol.HTTP_2)

      apply {
        this.url = url
      }

    fun includeIPv6(includeIPv6: Boolean) =
      apply {
        this.includeIPv6 = includeIPv6
      }

    fun post(post: Boolean) =
      apply {
        this.post = post
      }

    fun resolvePrivateAddresses(resolvePrivateAddresses: Boolean) =
      apply {
        this.resolvePrivateAddresses = resolvePrivateAddresses
      }

    return response.body().string();
  }
}
```


Post to a Server
----------------

This program posts data to a service. [Full source][post_example].

```java
public static final MediaType JSON = MediaType.get("application/json");

OkHttpClient client = new OkHttpClient();

String post(String url, String json) throws IOException {
  RequestBody body = RequestBody.create(json, JSON);

    networkLogs
      .assertLogEqual("--> POST $url http/1.1")
      .assertLogEqual("Content-Type: text/plain; charset=utf-8")
      .assertLogEqual("Content-Length: 3")
      .assertLogEqual("Host: $host")
      .assertLogEqual("Connection: Keep-Alive")
      .assertLogEqual("Accept-Encoding: gzip")
      .assertLogMatch(Regex("""User-Agent: okhttp/.+"""))
      .assertLogEqual("--> END POST")

      <post>******@****.***</post>
      <archive>http://mail-archives.apache.org/mod_mbox/maven-users</archive>
    </mailingList>
    <mailingList>
      <name>Maven Developer List</name>
      <subscribe>******@****.***</subscribe>
      <unsubscribe>******@****.***</unsubscribe>
      <post>******@****.***</post>

        add(buildCryptoSx(client)) // 521 - server down
      }
      add(buildChantra(client))
    }
  }

  private fun getByIp(host: String): InetAddress {
    return try {
      InetAddress.getByName(host)
    } catch (e: UnknownHostException) {
      // unlikely
      throw RuntimeException(e)
    }
  }

## Webhooks mit **FastAPI** und OpenAPI dokumentieren

Mit **FastAPI** können Sie mithilfe von OpenAPI die Namen dieser Webhooks, die Arten von HTTP-Operationen, die Ihre Anwendung senden kann (z. B. `POST`, `PUT`, usw.) und die Request**bodys** definieren, die Ihre Anwendung senden würde.

## Documenting webhooks with **FastAPI** and OpenAPI

With **FastAPI**, using OpenAPI, you can define the names of these webhooks, the types of HTTP operations that your app can send (e.g. `POST`, `PUT`, etc.) and the request **bodies** that your app would send.

       *
       * Example:
       * ```
       * --> POST /greeting http/1.1 (3-byte body)
       *
       * <-- 200 OK (22ms, 6-byte body)
       * ```
       */
      BASIC,

      /**
       * Logs request and response lines and their respective headers.
       *
       * Example:
       * ```
       * --> POST /greeting http/1.1
       * Host: example.com
       * Content-Type: plain/text

    includeIPv6: Boolean,
    post: Boolean = false,
  ): DnsOverHttps {
    val url = server.url("/lookup?ct")
    return DnsOverHttps.Builder().client(bootstrapClient)
      .includeIPv6(includeIPv6)
      .resolvePrivateAddresses(true)
      .url(url)
      .post(post)
      .build()
  }

  companion object {
    private fun address(host: String) = InetAddress.getByName(host)
  }