dnsResults =
      listOf(
        localhostIpv4,
        localhostIpv6,
      )

    client =
      clientTestRule.newClientBuilder()
        .eventListenerFactory(clientTestRule.wrap(listener))
        .connectTimeout(60, TimeUnit.SECONDS) // Deliberately exacerbate slow fallbacks.
        .dns { dnsResults }
        .fastFallback(true)
        .build()
    url =