code: def _update_dict(self, initial: JSON, other: Mapping) -> JSON:
          
          for key, value in other.items():
              if isinstance(value, collections.Mapping):
                  r = self._update_dict(initial.get(key, {}), value)
                  initial[key] = r
              else:
                  initial[key] = other[key]
          return initial
docs: Recursively update a dictionary.
  
          :param initial: Dict to update.
          :param other: Dict to update from.
          :return: Updated dict.