def check_required(self):
        for argument in self.arguments:
            if argument.required:
                raise ArgumentRequiredError(argument, self.tagname)
            else:
                self.kwargs[argument.name] = argument.get_default()
Iterate over arguments, checking if they're required, otherwise
dataset/ETHPy150Open ojii/django-classy-tags/classytags/parser.py/Parser.check_required