{"ast_node_type":"variable","tokens":[{"end":88,"kind":"keyword","start":0,"text":"let"}]}
                        let o = otherwise.get_or_insert_with(|| self.new_basic_block());
                        let next = self.new_basic_block();
                        if let Some((discr, c)) = self.lower_expr_to_some_operand(guard, then)? {