code: def _stop(self):
          
          # Unregisters the iPOPO service listener
          self.__context.remove_service_listener(self)
  
          try:
              # Try to register to factory events
              with use_ipopo(self.__context) as ipopo:
                  ipopo.remove_listener(self)
          except BundleException:
              # Service not present anymore
              pass
docs: Stops the instantiation queue (called by its bundle activator)