Java API: create a TestActorRef in the given system for the given props, with a random name.
Java API: create a TestActorRef in the given system for the given props, with the given name.
Java API: create a TestActorRef in the given system for the given props, with the given supervisor and a random name.
Java API: create a TestActorRef in the given system for the given props, with the given supervisor and name.