def _kwargs_keys_to_func_name(kwargs_key):
    """ Convert from self.kwargs key name to the function/method name

    Parameters
    ----------
    kwargs_key : str
        Key from self.kwargs dictionary

    Returns
    -------
    func_name : str
        Name of method or function associated with the input key

    """

    func_name = '_{:s}_rtn'.format(kwargs_key)
    return func_name