* [requestBodyOpen], [responseBodyOpen], and [expectMoreExchanges].
   *
   * This will release the connection if it is still held.
   *
   * It will also notify the listener that the call completed; either successfully or
   * unsuccessfully.
   *
   * If the call was canceled or timed out, this will wrap [e] in an exception that provides that

          if (multipleReadyTasks || !coordinatorWaiting && readyQueues.isNotEmpty()) {
            startAnotherThread()
          }

          return readyTask
        }

        // Notify the coordinator of a task that's coming up soon.
        coordinatorWaiting -> {
          if (minDelayNanos < coordinatorWakeUpAt - now) {
            backend.coordinatorNotify(this@TaskRunner)
          }

              if (errorExceptionToDeliver == null &&
                unacknowledgedBytesRead >= connection.okHttpSettings.initialWindowSize / 2
              ) {
                // Flow control: notify the peer that we're ready for more data! Only send a
                // WINDOW_UPDATE if the stream isn't in error.
                connection.writeWindowUpdateLater(id, unacknowledgedBytesRead)

    connection.lock.assertHeld()

    connections.add(connection)
//    connection.queueEvent { connectionListener.connectEnd(connection) }
    scheduleCloser()
  }

  /**
   * Notify this pool that [connection] has become idle. Returns true if the connection has been
   * removed from the pool and should be closed.
   */
  fun connectionBecameIdle(connection: RealConnection): Boolean {