* [Request.tag]. Use null to remove any existing tag assigned for [T].
     *
     * Use this API to attach timing, debugging, or other application data to a request so that
     * you may read it in interceptors, event listeners, or callbacks.
     */
    @JvmName("reifiedTag")
    inline fun <reified T : Any> tag(tag: T?): Builder = tag(T::class, tag)

    /**

import org.junit.platform.launcher.core.LauncherConfig
import org.junit.platform.launcher.core.LauncherDiscoveryRequestBuilder
import org.junit.platform.launcher.core.LauncherFactory
import org.junit.platform.launcher.listeners.SummaryGeneratingListener

/**
 * Graal main method to run tests with minimal reflection and automatic settings.
 * Uses the test list in native-image-tests/src/main/resources/testlist.txt.
 */

 * [RFC 2817][1]. The HTTP CONNECT request that creates this tunnel connection is special: it
 * does not participate in any [interceptors][Interceptor] or [event listeners][EventListener]. It
 * doesn't include the motivating request's HTTP headers or even its full URL; only the target
 * server's hostname is sent to the proxy.
 *

  @Synchronized fun receivedPongCount(): Int = receivedPongCount

  @Throws(IOException::class)
  override fun onReadMessage(text: String) {
    listener.onMessage(this, text)
  }

  @Throws(IOException::class)
  override fun onReadMessage(bytes: ByteString) {
    listener.onMessage(this, bytes)
  }

  @Synchronized override fun onReadPing(payload: ByteString) {

However, while we chose to use the xDS *transport protocol*, we chose to not use the xDS resource types, such as Clusters and Listeners.
In our experience and testing, these types force us to represent data in inefficient ways because they are general purpose.
Ztunnel is not general purpose; it has an extremely tight goal.

  /** Uses [request] to connect a new web socket. */
  override fun newWebSocket(
    request: Request,
    listener: WebSocketListener,
  ): WebSocket {
    val webSocket =
      RealWebSocket(
        taskRunner = taskRunner,
        originalRequest = request,
        listener = listener,
        random = Random(),
        pingIntervalMillis = pingIntervalMillis.toLong(),

    server.processNextFrame()
    client.listener.assertClosing(1000, "Hello!")
    server.listener.assertClosing(1000, "Hi!")
    client.webSocket!!.finishReader()
    server.webSocket!!.finishReader()
    client.listener.assertClosed(1000, "Hello!")
    server.listener.assertClosed(1000, "Hi!")
    taskFaker.runTasks()
    assertThat(client.closed).isTrue()

    // In the process we made one successful connection attempt.
    assertThat(listener.recordedEventTypes().filter { it == "ConnectStart" }).hasSize(2)
    assertThat(listener.recordedEventTypes().filter { it == "ConnectFailed" }).hasSize(1)
    assertThat(listener.recordedEventTypes().filter { it == "ConnectEnd" }).hasSize(1)
  }

  @Test
  fun reachesIpv6WhenIpv4IsDown() {

NAME                   ADDRESSES PORT  MATCH DESTINATION
listener/main_internal           0     ALL   Cluster: inbound-vip|8100|http|httpbin.default.svc.cluster.local
listener/main_internal           0     ALL   Cluster: inbound-vip|8000|http|httpbin.default.svc.cluster.local
listener/main_internal           0     ALL   Cluster: encap
listener/main_internal           0     ALL   Cluster: encap
listener/              0.0.0.0   15021 ALL   Inline Route: /healthz/ready*

        .build().also {
          listener.satisfactionFailure(call, it)
        }
    }

    // If we don't need the network, we're done.
    if (networkRequest == null) {
      return cacheResponse!!.newBuilder()
        .cacheResponse(cacheResponse.stripBody())
        .build().also {
          listener.cacheHit(call, it)
        }
    }

    if (cacheResponse != null) {