/** Returns the connection to use, which might be different from [connection]. */
  override fun handleSuccess(): RealConnection {
    user.updateRouteDatabaseAfterSuccess(route)

    val connection = this.connection!!
    user.connectionConnectEnd(connection, route)

    // If we raced another call connecting to this host, coalesce the connections. This makes for
    // 3 different lookups in the connection pool!

    }

  /**
   * A callback to be invoked each time the dispatcher becomes idle (when the number of running
   * calls returns to zero).
   *
   * Note: The time at which a [call][Call] is considered idle is different depending on whether it
   * was run [asynchronously][Call.enqueue] or [synchronously][Call.execute]. Asynchronous calls
   * become idle after the [onResponse][Callback.onResponse] or [onFailure][Callback.onFailure]

    without stabilizing these new APIs first.

    Do not use these experimental APIs in modules that may be executed using a version of OkHttp
    different from the version that the module was compiled with. Do not use them in published
    libraries. Do not use them if you aren't willing to track changes to them.

 *  Breaking: Drop support for Kotlin Multiplatform.

          val newStream = Http2Stream(streamId, this@Http2Connection, false, inFinished, headers)
          lastGoodStreamId = streamId
          streams[streamId] = newStream

          // Use a different task queue for each stream because they should be handled in parallel.
          taskRunner.newQueue().execute("$connectionName[$streamId] onStream") {
            try {
              listener.onStream(newStream)

   *  * The second race is between plan2 and plan3, with a 250 ms head start for plan2.
   *
   * We get plan0 and plan1 from the route planner.
   * We get plan2 as a follow-up to plan1, typically retry the same IP but different TLS.
   * We get plan3 as a retry of plan0, which was canceled when it lost the race.
   *
   * This test confirms that we prefer to do the TLS follow-up (plan2) before the TCP retry (plan3).