10:28:22,289 AM [testsystem-pekko.actor.default-dispatcher-6] [INFO] Slf4jLogger - Slf4jLogger started
10:28:22,632 AM [testsystem-pekko.actor.default-dispatcher-7] [INFO] RepointableActorRef -  pekkoDeadLetter Message [java.lang.String] from Actor[pekko://testsystem/system/testActor-13#-1550939752] to Actor[pekko://testsystem/user/pingpongactor#-2100416270] was not delivered. [1] dead letters encountered. If this is not an expected behavior then Actor[pekko://testsystem/user/pingpongactor#-2100416270] 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'.
10:28:22,641 AM [testsystem-pekko.actor.default-dispatcher-9] [INFO] CoordinatedShutdown - Running CoordinatedShutdown with reason [ActorSystemTerminateReason]