def visit_subscript(self, node, parent):
        """visit a Subscript node by returning a fresh instance of it"""
        context = self._get_context(node)
        newnode = nodes.Subscript(
            ctx=context, lineno=node.lineno, col_offset=node.col_offset, parent=parent
        )
        newnode.postinit(
            self.visit(node.value, newnode), self.visit(node.slice, newnode)
        )
        return newnode
visit a Subscript node by returning a fresh instance of it