Can Use Case Model Packages contain only Use Cases, or do Actors need to be involved as well?  For example, suppose I have a "Shipping" Package.  Can it contain only the Use Cases "Deliver Products" and "Receive Products"?  Can the actor only interact with the "Shipping" Package which contains the two Use Cases?

TIA,

vinny

Thanks, Adrian.  I've had a difficult time finding examples of Use Case Packages!