Method is_optional

mypy/nodes.py:2493–2494

(self)

        return self == ARG_POS or self == ARG_NAMED

    def is_optional(self) -> bool:
        return self == ARG_OPT or self == ARG_NAMED_OPT

    def is_star(self) -> bool:
        return self == ARG_STAR or self == ARG_STAR2