code: def _dictify(field, value):
      
      if value is None:
          return None
      elif field.type_:
          return value.to_dict()
      return field.dict_value(value)
docs: Make `value` suitable for a dictionary.
  
      * If `value` is an Entity, call to_dict() on it.
      * If value is a timestamp, turn it into a string value.
      * If none of the above are satisfied, return the input value