12:56:27,920 PM [testsystem-pekko.actor.default-dispatcher-5] [INFO] Slf4jLogger - Slf4jLogger started
12:56:28,239 PM [testsystem-pekko.actor.default-dispatcher-5] [INFO] RepointableActorRef -  pekkoDeadLetter Message [java.lang.String] from Actor[pekko://testsystem/system/testActor-13#-789423158] to Actor[pekko://testsystem/user/pingpongactor#-1595195889] was not delivered. [1] dead letters encountered. If this is not an expected behavior then Actor[pekko://testsystem/user/pingpongactor#-1595195889] may have terminated unexpectedly. This logging can be turned off or adjusted with configuration settings 'pekko.log-dead-letters' and 'pekko.log-dead-letters-during-shutdown'.
12:56:28,250 PM [testsystem-pekko.actor.default-dispatcher-7] [INFO] CoordinatedShutdown - Running CoordinatedShutdown with reason [ActorSystemTerminateReason]