code: def _set_notification(self, hit_type, transport, destination, event_types=None):
          
          assert type(hit_type) is str, "hit_type argument should be a string."
          
          params = {'HITTypeId': hit_type}
          
          # from the Developer Guide:
          # The 'Active' parameter is optional. If omitted, the active status of
          # the HIT type's notification specification is unchanged. All HIT types
          # begin with their notification specifications in the "inactive" status.
          notification_params = {'Destination': destination,
                                 'Transport': transport,
                                 'Version': boto.mturk.notification.NotificationMessage.NOTIFICATION_VERSION,
                                 'Active': True,
                                 }
  
          # add specific event types if required
          if event_types:
              self.build_list_params(notification_params, event_types, 'EventType')
          
          # Set up dict of 'Notification.1.Transport' etc. values
          notification_rest_params = {}
          num = 1
          for key in notification_params:
              notification_rest_params['Notification.%d.%s' % (num, key)] = notification_params[key]
          
          # Update main params dict
          params.update(notification_rest_params)
          
          # Execute operation
          return self._process_request('SetHITTypeNotification', params)
docs: Common SetHITTypeNotification operation to set notification for a
          specified HIT type