{"ast_node_type":"other","tokens":[{"end":95,"kind":"keyword","start":0,"text":"this.expect_one_of(&[exp!(Comma)],"}]}
                    this.expect_one_of(&[exp!(Comma)], &[exp!(CloseBrace)]).map_err(|mut err| {
                    arm_body = Some(expr);
                        if this.token == token::FatArrow {