def shutdown_service_server(service)
      begin
        @master.unregister_service(service.service_name,
                                   service.service_uri)
        @service_servers.delete(service) do |pub|
          raise "service_server not found"
        end
      ensure
        service.close
      end
    end
def shutdown_service_server(service)
      begin
        @master.unregister_service(service.service_name,
                                   service.service_uri)
        @service_servers.delete(service) do |pub|
          raise "service_server not found"
        end
      ensure
        service.close
      end
    end
shutdown a service server.
 @param [ServiceServer] service ServiceServer to be shutdown