// If there's a "Expect: 100-continue" header on the request, wait for a "HTTP/1.1 100
        // Continue" response before transmitting the request body. If we don't get that, return
        // what we did get (such as a 4xx response) without ever transmitting the request body.
        if ("100-continue".equals(request.header("Expect"), ignoreCase = true)) {
          exchange.flushRequest()

  DISCONNECT_DURING_RESPONSE_BODY,
  DO_NOT_READ_REQUEST_BODY,
  FAIL_HANDSHAKE,
  SHUTDOWN_INPUT_AT_END,
  SHUTDOWN_OUTPUT_AT_END,
  STALL_SOCKET_AT_START,
  NO_RESPONSE,
  RESET_STREAM_AT_START,
  EXPECT_CONTINUE,
  CONTINUE_ALWAYS,

        }
        .build()

    executeSynchronously(request)
      .assertBody("body")

    assertThat(client.routeDatabase.failedRoutes).isEmpty()
    // TODO check if we expect a second request to server1, before attempting server2
    assertThat(server1.requestCount).isEqualTo(2)
    assertThat(server2.requestCount).isEqualTo(1)

          try {
            bodyRef.set(response.body.string())
          } catch (e: IOException) {
            // It is ok if this broke the stream.
            bodyRef.set("A")
            throw e // We expect to not loop into onFailure in this case.
          } finally {
            latch.countDown()
          }
        }
      },
    )
    latch.await()
    assertThat(bodyRef.get()).isEqualTo("A")

  }

  result.settings(settings)
  result.status = status
  result.headers(headers)
  result.trailers(trailers)
  result.socketPolicy =
    when (socketPolicy) {
      SocketPolicy.EXPECT_CONTINUE, SocketPolicy.CONTINUE_ALWAYS -> {
        result.add100Continue()
        KeepOpen
      }
      SocketPolicy.UPGRADE_TO_SSL_AT_END -> {
        result.inTunnel()
        KeepOpen
      }

 *  * [onRequest]
 *  * [onHeaders] (unless canceled)
 *  * [onData] (optional sequence of data frames)
 *
 * As a stream ID is scoped to a single HTTP/2 connection, implementations which target multiple
 * connections should expect repetition of stream IDs.
 *
 * Return true to request cancellation of a pushed stream.  Note that this does not guarantee
 * future frames won't arrive on the stream ID.
 */
interface PushObserver {
  /**

    server.enqueue(MockResponse().setBody("response"))
    val url = server.url("/").toUrl()
    val connection = url.openConnection() as HttpURLConnection
    connection.setDoOutput(true)
    connection.setRequestProperty("Expect", "100-Continue")
    connection.outputStream.write("request".toByteArray(StandardCharsets.UTF_8))
    val inputStream = connection.inputStream

  private var coordinatorWaiting = false
  private var coordinatorWakeUpAt = 0L

  /**
   * When we need a new thread to run tasks, we call [Backend.execute]. A few microseconds later we
   * expect a newly-started thread to call [Runnable.run]. We shouldn't request new threads until
   * the already-requested ones are in service, otherwise we might create more threads than we need.
   *

  )

  fun toDer(value: T): ByteString {
    val buffer = Buffer()
    val writer = DerWriter(buffer)
    toDer(writer, value)
    return buffer.readByteString()
  }

  /**
   * Returns an adapter that expects this value wrapped by another value. Typically this occurs
   * when a value has both a context or application tag and a universal tag.
   *
   * Use this for EXPLICIT tag types:
   *
   * ```
   * [5] EXPLICIT UTF8String

  sink(file).use {
    try {
      delete(file)
      return true
    } catch (_: IOException) {
    }
  }
  delete(file)
  return false
}

/** Delete file we expect but don't require to exist. */
internal fun FileSystem.deleteIfExists(path: Path) {
  try {
    delete(path)
  } catch (fnfe: FileNotFoundException) {
    return
  }
}