{"ast_node_type":"function","tokens":[{"end":78,"kind":"keyword","start":0,"text":"fn"}]}
    fn into_diag(self, dcx: DiagCtxtHandle<'_>, level: Level) -> Diag<'_, G> {
    #[track_caller]
        let mut diag = Diag::new(dcx, level, fluent::metadata_invalid_meta_files);