enableProtocol(Protocol.HTTP_2)
    val body =
      MockStreamHandler()
        .receiveRequest("request A\n")
        .sendResponse("response B\n")
        .receiveRequest("request C\n")
        .sendResponse("response D\n")
        .receiveRequest("request E\n")
        .sendResponse("response F\n")
        .exhaustRequest()
        .exhaustResponse()
    server.enqueue(
      MockResponse.Builder()

        try {
          stream.requestBody.exhausted()
          throw AssertionError("expected IOException")
        } catch (expected: IOException) {
        }
      }
    }

  @JvmOverloads
  fun sendResponse(
    s: String,
    responseSent: CountDownLatch = CountDownLatch(0),
  ) = apply {
    actions += { stream ->
      stream.responseBody.writeUtf8(s)
      stream.responseBody.flush()
      responseSent.countDown()

			case <-m.ctx.Done():
				return
			case handlerIn <- in:
				m.send(message{Op: OpUnblockClMux, MuxID: m.ID, Flags: c.baseFlags})
			}
		}
	}
}

// sendResponses will send responses to the client.
func (m *muxServer) sendResponses(ctx context.Context, toSend <-chan []byte, c *Connection, handlerErr *atomic.Pointer[RemoteErr], outBlock <-chan struct{}) {
	for {
		// Process outgoing message.
		var payload []byte