text: # from snr.core import *
  # from snr.prelude import *
  # from snr.prelude import *
  
  
  # class KalmanEndpoint(Endpoint):
  #     def __init__(self,
  #                  factory: EndpointFactory,
  #                  parent: AbstractNode,
  #                  name: str,
  #                  input_data_key: DataKey,
  #                  output_data_key: DataKey
  #                  ) -> None:
  #         super().__init__(factory,
  #                          parent,
  #                          name)
  #         self.task_handlers = {
  #             (TaskType.store_page, input_data_key):
  #             self.filter
  #         }
  #         self.input_data_key = input_data_key
  #         self.output_data_key = output_data_key
  
  #     def task_source(self) -> None:
  #         return None
  
  #     def filter(self, t: Task, k: TaskId) -> SomeTasks:
  #         assert isinstance(t.val_list[0], Page) and \
  #             isinstance(t.val_list[0].data, str)
  #         input = t.val_list[0].data
  #         # TODO: Use Kalman filter implementation
  #         output: str = input  # No op
  #         return self.task_store_data(self.output_data_key, output)
  
  #     def begin(self) -> None:
  #         pass
  
  #     def halt(self) -> None:
  #         pass
  
  #     def terminate(self) -> None:
  #         pass
  