{"ast_node_type":"function","tokens":[{"end":56,"kind":"keyword","start":0,"text":"fn"}]}
            fn check_arm(a: &'tcx rustc_hir::Arm<'tcx>);
            fn check_stmt(a: &'tcx rustc_hir::Stmt<'tcx>);
            fn check_pat(a: &'tcx rustc_hir::Pat<'tcx>);