Latest version of com.typesafe.akka:akka-actor_2.12.0-M4
https://javadoc.io/doc/com.typesafe.akka/akka-actor_2.12.0-M4
Current version 2.4.6
https://javadoc.io/doc/com.typesafe.akka/akka-actor_2.12.0-M4/2.4.6
package-list path (used for javadoc generation -link option)
https://javadoc.io/doc/com.typesafe.akka/akka-actor_2.12.0-M4/2.4.6/package-list