val callFailed: CallFailed = listener.removeUpToEvent<CallFailed>()
    assertThat(callFailed.call).isSameAs(call)
    assertThat(callFailed.ioe).isInstanceOf<UnknownHostException>()
  }

  @Test
  fun emptyDnsLookup() {
    val emptyDns = Dns { listOf() }
    client =
      client.newBuilder()
        .dns(emptyDns)
        .build()
    val call =
      client.newCall(
        Request.Builder()