def get(self, key: K) -> TOption[T]:
        """
        :param key:

        Usage:

            >>> TDict(k1=1, k2=2, k3=3).get("k2")
            Option --> 2
            >>> TDict(k1=1, k2=2, k3=3).get("unknown")
            Option --> None
        """
        return TOption(self[key]) if key in self else TOption(None)