{"ast_node_type":"variable","tokens":[{"end":65,"kind":"keyword","start":0,"text":"if"}]}
        if let PatKind::Struct(ref qpath, fields, _) = pat.kind {
    fn visit_pat(&mut self, pat: &'tcx hir::Pat<'tcx>) {
            let res = self.typeck_results().qpath_res(qpath, pat.hir_id);