code: def unregister_service(self, registration):
          # type: (ServiceRegistration) -> bool
          
          # Get the Service Reference
          reference = registration.get_reference()
  
          # Remove the service from the registry
          svc_instance = self._registry.unregister(reference)
  
          # Keep a track of the unregistering reference
          self.__unregistering_services[reference] = svc_instance
  
          # Call the listeners
          event = ServiceEvent(ServiceEvent.UNREGISTERING, reference)
          self._dispatcher.fire_service_event(event)
  
          # Update the bundle registration information
          bundle = reference.get_bundle()
          bundle._unregistered_service(registration)
  
          # Remove the unregistering reference
          del self.__unregistering_services[reference]
          return True
docs: Unregisters the given service
  
          :param registration: A ServiceRegistration to the service to unregister
          :raise BundleException: Invalid reference