def advertise_service(service_name, service_type, &callback)
      server = ::ROS::ServiceServer.new(@node_name,
                                        resolve_name(service_name),
                                        service_type,
                                        callback,
                                        @manager.host)
      @manager.add_service_server(server)
      trap_signals
      server
    end
def advertise_service(service_name, service_type, &callback)
      server = ::ROS::ServiceServer.new(@node_name,
                                        resolve_name(service_name),
                                        service_type,
                                        callback,
                                        @manager.host)
      @manager.add_service_server(server)
      trap_signals
      server
    end
start service server.

 @param [String] service_name name of this service (string)
 @param [Service] service_type service class
 @param [Proc] callback service definition
 @return [ServiceServer] ServiceServer instance