class_docstr: A helper class that represents input string that to be modified.
code: def field_value(self, value):
      # check field value type
      if self._field_type is not None and not isinstance(
          value, self._field_type
      ):
          raise ValueError(
              "Invalid input type {0} (required {1})".format(
                  type(value), self._field_type
              )
          )
  
      self._field_value = value
  
label_desc: Use image node_id 5 for calling the Field obj's underlying member method code with example usage: obj.field_value(value) without return types