10:28:17,266 AM [testsystem-akka.actor.default-dispatcher-6] [INFO] Slf4jLogger - Slf4jLogger started
10:28:17,576 AM [testsystem-akka.actor.default-dispatcher-8] [INFO] RepointableActorRef -  akkaDeadLetter Message [java.lang.String] from Actor[akka://testsystem/system/testActor-30#1604220635] to Actor[akka://testsystem/user/pingpongactor#-1543401051] was not delivered. [1] dead letters encountered. If this is not an expected behavior then Actor[akka://testsystem/user/pingpongactor#-1543401051] 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'.
10:28:17,576 AM [testsystem-akka.actor.default-dispatcher-8] [INFO] CoordinatedShutdown - Running CoordinatedShutdown with reason [ActorSystemTerminateReason]