{"ast_node_type":"variable","tokens":[{"end":68,"kind":"keyword","start":0,"text":"if"}]}
        if let Some(idx) = self.param_def_id_to_index.get(&def_id) {
    pub fn param_def_id_to_index(&self, tcx: TyCtxt<'tcx>, def_id: DefId) -> Option<u32> {
            Some(*idx)