code: def create_jsonable_registry(self):
      
      # JSON does not support tuples as keys. Only strings. Therefore, we store
      # the device name, tensor name, and dictionary data within a 3-item list.
      return [HistoryTriplet(pair[0], pair[1], history.create_jsonable_history())
              for (pair, history) in self._data.items()]
docs: Creates a JSON-able representation of this object.
  
      Returns:
        A dictionary mapping (device, tensor name) to JSON-able object
        representations of NumericsAlertHistory.