11:21:34,617 AM [testsystem-akka.actor.default-dispatcher-4] [INFO] Slf4jLogger - Slf4jLogger started
11:21:34,841 AM [testsystem-akka.actor.default-dispatcher-6] [INFO] RepointableActorRef - Message [java.lang.String] from Actor[akka://testsystem/system/testActor-51#-972150643] to Actor[akka://testsystem/user/pingpongactor#-1357477837] was not delivered. [1] dead letters encountered. If this is not an expected behavior then Actor[akka://testsystem/user/pingpongactor#-1357477837] may have terminated unexpectedly. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.
11:21:34,850 AM [testsystem-akka.actor.default-dispatcher-4] [INFO] CoordinatedShutdown - Running CoordinatedShutdown with reason [ActorSystemTerminateReason]