def get_nom_val(atrv):
r_nominal = re.compile('<STR_LIT>')<EOL>m = r_nominal.match(atrv)<EOL>if m:<EOL><INDENT>return tuple(i.strip() for i in m.group(<NUM_LIT:1>).split('<STR_LIT:U+002C>'))<EOL><DEDENT>else:<EOL><INDENT>raise ValueError("<STR_LIT>")<EOL><DEDENT>
Given a string containing a nominal type, returns a tuple of the
    possible values.

    A nominal type is defined as something framed between braces ({}).

    Parameters
    ----------
    atrv : str
       Nominal type definition

    Returns
    -------
    poss_vals : tuple
       possible values

    Examples
    --------
    >>> get_nom_val("{floup, bouga, fl, ratata}")
    ('floup', 'bouga', 'fl', 'ratata')