Download a file, print its headers, and print its response body as a string.

The `string()` method on response body is convenient and efficient for small documents. But if the response body is large (greater than 1 MiB), avoid `string()` because it will load the entire document into memory. In that case, prefer to process the body as a stream.

=== ":material-language-kotlin: Kotlin"
    ```kotlin

        .setHeader("content-type", "text/event-stream")
        .body("data: hey\n\n")
        .build(),
    )
    newEventSource()
    listener.assertFailure("timeout")
  }

  @Test
  fun retainsAccept() {
    server.enqueue(
      MockResponse
        .Builder()
        .body(
          """
          |data: hey
          |
          |
          """.trimMargin(),

  // the call, but they may be accessed by other threads for duplex requests.

  /** True if this call still has a request body open. */
  private var requestBodyOpen = false

  /** True if this call still has a response body open. */
  private var responseBodyOpen = false

  /** True if there are more exchanges expected for this call. */
  private var expectMoreExchanges = true

      if (!response.isSuccessful) {
        listener.onFailure(this, null, response)
        return
      }

      val body = response.body

      if (!body.isEventStream()) {
        listener.onFailure(
          this,
          IllegalStateException("Invalid content-type: ${body.contentType()}"),
          response,
        )
        return
      }

  fun failureWith401IsReadable() {
    server.enqueue(
      MockResponse(
        code = 401,
        body = "{\"error\":{\"message\":\"No auth credentials found\",\"code\":401}}",
        headers = Headers.headersOf("content-type", "application/json"),
      ),
    )
    server.enqueue(
      MockResponse(
        body =
          """
          |data: hey
          |
          |
          """.trimMargin(),

        .build()

    client.newCall(request).execute().use { response ->
      if (!response.isSuccessful) throw IOException("Unexpected code $response")
      println(response.body.string())
    }
  }

  private class ProgressRequestBody(
    private val delegate: RequestBody,
    private val progressListener: ProgressListener,
  ) : RequestBody() {

    OkHttpClient client = new OkHttpClient();
    EventSource.Factory factory = EventSource.Factory.create(client);
    server.enqueue(
      new MockResponse.Builder()
        .body("data: hello\n\n")
        .setHeader("content-type", "text/event-stream")
        .build()
    );
    Request request = new Request.Builder().url(server.url("/")).build();

  override fun onFailure(
    eventSource: EventSource,
    t: Throwable?,
    response: Response?,
  ) {
    get().log("[ES] onFailure", Platform.INFO, t)
    events.add(Failure(t, response, t?.message ?: response?.body?.string()))
    drainCancelQueue(eventSource)
  }

  private fun drainCancelQueue(eventSource: EventSource) {
    if (cancel) {
      cancel = false
      eventSource.cancel()
    }
  }

        Request
          .Builder()
          .url(server.url("/"))
          .build(),
      )
    val response = call.execute()
    interruptLater(500)
    val responseBody = response.body.byteStream()
    val buffer = ByteArray(1024)
    assertFailsWith<IOException> {
      while (responseBody.read(buffer) != -1) {
      }
    }
    responseBody.close()
  }

  @Test

      .build();

    Response response = client.newCall(request).execute();
    if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

    System.out.println(response.body().string());
  }

  public static void main(String... args) throws Exception {
    new UploadProgress().run();
  }

  private static class ProgressRequestBody extends RequestBody {