Return the string associated to the parameters_off

            :rtype: string

def get_parameters_off_value(self):
        """
            Return the string associated to the parameters_off

            :rtype: string
        """
        if self.parameters_off_value == None:
            params = self.CM.get_type_list(self.parameters_off)
            self.parameters_off_value = '({})'.format(' '.join(params))
        return self.parameters_off_value