code: def service_changed(self, event):
          # type: (ServiceEvent) -> None
          
          kind = event.get_kind()
          if kind == ServiceEvent.REGISTERED:
              # iPOPO service registered: register to factory events
              with use_ipopo(self.__context) as ipopo:
                  ipopo.add_listener(self)
docs: Handles an event about the iPOPO service