def METHOD_NAME(self):
    """Number of parameters and their names.
    :return: int, list of parameter names
    """
    num, name_list = 0, []
    for k, param_group in enumerate(self.param_groups):
        n, names = ModelParamGroup.compose_num_params(
            param_group, kwargs_fixed=self.kwargs_fixed[k]
        )
        num += n
        name_list += names
    return num, name_list