assertThat(firstResponseCode.get()).isEqualTo(0)
    // Second response is done.
    assertThat(secondResponseCode.get()).isEqualTo(200)
    latch.countDown()
    startsFirst.join()
    // And now it's done!
    assertThat(firstResponseCode.get()).isEqualTo(200)
    // (Still done).
    assertThat(secondResponseCode.get()).isEqualTo(200)
  }

  private fun buildRequestThread(
    path: String,