latch.await()
          }
          return MockResponse()
        }
      }
    mockWebServer.dispatcher = dispatcher
    val startsFirst = buildRequestThread(firstRequest, firstResponseCode)
    startsFirst.start()
    val endsFirst = buildRequestThread(secondRequest, secondResponseCode)
    endsFirst.start()
    endsFirst.join()
    // First response is still waiting.
    assertThat(firstResponseCode.get()).isEqualTo(0)