10:21:15,179 PM [testsystem-akka.actor.default-dispatcher-6] [INFO] Slf4jLogger - Slf4jLogger started
10:21:15,505 PM [testsystem-akka.actor.default-dispatcher-6] [INFO] RepointableActorRef -  akkaDeadLetter Message [java.lang.String] from Actor[akka://testsystem/system/testActor-1#-1871935139] to Actor[akka://testsystem/user/pingpongactor#-1289850510] was not delivered. [1] dead letters encountered. If this is not an expected behavior then Actor[akka://testsystem/user/pingpongactor#-1289850510] 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'.
10:21:15,514 PM [testsystem-akka.actor.default-dispatcher-6] [INFO] CoordinatedShutdown - Running CoordinatedShutdown with reason [ActorSystemTerminateReason]