How to use the d20.Parenthetical function in d20

else:
                tokens = []
                for t in _resist_tokenize(node.annotation.lower()):
                    tokens.extend(_resist_tokenize(transforms.get(t, t)))
            original_annotation = node.annotation
            dtype = f"{' '.join(always)} {' '.join(tokens)}".strip()
            node.annotation = f"[{dtype}]"

            # handle tree modification
            ann = set(tokens) | always

            if any(n.applies_to(ann) for n in resistances.neutral):  # neutral overrides all
                return node

            if any(v.applies_to(ann) for v in resistances.vuln):
                node = d20.BinOp(d20.Parenthetical(node), '*', d20.Literal(2))

            if original_annotation.startswith('[^') or original_annotation.endswith('^]'):
                node.annotation = original_annotation
                # break here - don't handle resist/immune
                return node

            if any(r.applies_to(ann) for r in resistances.resist):
                node = d20.BinOp(d20.Parenthetical(node), '/', d20.Literal(2))

            if any(im.applies_to(ann) for im in resistances.immune):
                node = d20.BinOp(d20.Parenthetical(node), '*', d20.Literal(0))

            return node

        for i, child in enumerate(node.children):
            replacement = do_visit(child)