call.execute().use { response ->
      val source = response.body.source()
      assertThat(response.header("h1")).isEqualTo("v1")
      assertThat(source.readUtf8(5)).isEqualTo("Hello")
      call.cancelLater(500.milliseconds)
      val trailersDelay =
        measureTime {
          val exception =
            assertFailsWith<IOException> {
              response.trailers()
            }

      client.newCall(
        Request(
          server
            .url("/")
            .newBuilder()
            .scheme(scheme!!)
            .build(),
        ),
      )
    cancelLater(call, cancelDelayMillis)
    val startNanos = System.nanoTime()
    assertFailsWith<IOException> {
      call.execute()
    }
    val elapsedNanos = System.nanoTime() - startNanos