{"ast_node_type":"other","tokens":[{"end":98,"kind":"keyword","start":0,"text":"//"}]}
        // FIXME: This error message isn't great, but it doesn't show up in the existing UI tests,
    fn fallback_error(&self, tcx: TyCtxt<'tcx>, span: Span) -> Diag<'tcx> {
        // and is only the fallback when the nice error fails. Consider improving this some more.