code: def set_target_ref(self, value):
          
          if value is None or not isinstance(value, str):
              raise TypeError("TargetRef is required and must be set to a String")
          else:
              self.__target_ref = value
docs: Setter for 'target_ref' field.
          :param value - a new value of 'target_ref' field. Required field. Must be a String type.