https://pekko.apache.org/japi/pekko/snapshot/org/apache/pekko/remote/SystemMessageFormats.SystemMessage.html
SystemMessageFormats.SystemMessage
declaration: package: org.apache.pekko.remote, class: SystemMessageFormats, class: SystemMessage
https://pekko.apache.org/japi/pekko/current/org/apache/pekko/remote/SystemMessageFormats.SuperviseData.html
SystemMessageFormats.SuperviseData
https://pekko.apache.org/japi/pekko/current/org/apache/pekko/remote/SystemMessageFormats.WatchData.Builder.html
SystemMessageFormats.WatchData.Builder
watchdatabuilder