val response1 = responses.take()
    assertThat(response1).isEqualTo("")
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)

    // Now make the second request which will restrict the first HTTP/2 connection from creating new
    // streams.
    client.newCall(request).enqueue(callback)
    val response2 = responses.take()
    assertThat(response2).isEqualTo("DEF")