code: def _app_config_select(self, request, obj):
          
          if not obj and not request.GET.get(self.app_config_attribute, False):
              config_model = get_apphook_model(self.model, self.app_config_attribute)
              if config_model.objects.count() == 1:
                  return config_model.objects.first()
              return None
          elif obj and getattr(obj, self.app_config_attribute, False):
              return getattr(obj, self.app_config_attribute)
          elif request.GET.get(self.app_config_attribute, False):
              config_model = get_apphook_model(self.model, self.app_config_attribute)
              return config_model.objects.get(
                  pk=int(request.GET.get(self.app_config_attribute, False))
              )
          return False
docs: Return the select value for apphook configs
  
          :param request: request object
          :param obj: current object
          :return: False if no preselected value is available (more than one or no apphook
                   config is present), apphook config instance if exactly one apphook
                   config is defined or apphook config defined in the request or in the current
                   object, False otherwise