Since this example starts the feeder actor locally and actorStream does not connect to any remote feeder actor, the <hostname> is always going to be localhost. So it does not make sense to have hostname as a command line parameter. There are two ways that makes sense - 
(1) either remove the <hostname> as a command-line parameter and have it always be "localhost" in the code.
(2) or, allow the Feeder actor to be start separately from the command line (using another object and main function) and then the ActorWordCount can take the <hostname> + <port> to connect to the feeder. This is much like the nc and NetworkWordCount. And its also more practical usecase that running locally and therefore cooler.