{"ast_node_type":"function","tokens":[{"end":80,"kind":"keyword","start":0,"text":"fn"}]}
    fn parse_borrow_modifiers(&mut self) -> (ast::BorrowKind, ast::Mutability) {
    /// Parse `mut?` or `[ raw | pin ] [ const | mut ]`.
        if self.check_keyword(exp!(Raw)) && self.look_ahead(1, Token::is_mutability) {