def _last_index(self, s):
        self.set_index(max(0, self._find_one_after_last_labeled_index() - 1))
def myfunc(first, second=None, third=Optional(5), fourth=Optional(execute=list)):
            #Equivalent: second = deoption(second, 5)
            if isinstance(second, type(None)):
                second = 5