def _test(value, *args, **keywargs):
    """
    A function that exists for test purposes.
    
    >>> checks = [
    ...     '3, 6, min=1, max=3, test=list(a, b, c)',
    ...     '3',
    ...     '3, 6',
    ...     '3,',
    ...     'min=1, test="a b c"',
    ...     'min=5, test="a, b, c"',
    ...     'min=1, max=3, test="a, b, c"',
    ...     'min=-100, test=-99',
    ...     'min=1, max=3',
    ...     '3, 6, test="36"',
    ...     '3, 6, test="a, b, c"',
    ...     '3, max=3, test=list("a", "b", "c")',
    ...     '''3, max=3, test=list("'a'", 'b', "x=(c)")''',
    ...     "test='x=fish(3)'",
    ...    ]
    >>> v = Validator({'test': _test})
    >>> for entry in checks:
    ...     print v.check(('test(%s)' % entry), 3)
    (3, ('3', '6'), {'test': ['a', 'b', 'c'], 'max': '3', 'min': '1'})
    (3, ('3',), {})
    (3, ('3', '6'), {})
    (3, ('3',), {})
    (3, (), {'test': 'a b c', 'min': '1'})
    (3, (), {'test': 'a, b, c', 'min': '5'})
    (3, (), {'test': 'a, b, c', 'max': '3', 'min': '1'})
    (3, (), {'test': '-99', 'min': '-100'})
    (3, (), {'max': '3', 'min': '1'})
    (3, ('3', '6'), {'test': '36'})
    (3, ('3', '6'), {'test': 'a, b, c'})
    (3, ('3',), {'test': ['a', 'b', 'c'], 'max': '3'})
    (3, ('3',), {'test': ["'a'", 'b', 'x=(c)'], 'max': '3'})
    (3, (), {'test': 'x=fish(3)'})
    """
    return (value, args, keywargs)