{"ast_node_type":"function","tokens":[{"end":94,"kind":"keyword","start":0,"text":"fn"}]}
    fn xform_method_sig(&self, method: DefId, args: GenericArgsRef<'tcx>) -> ty::FnSig<'tcx> {
    #[instrument(level = "debug", skip(self))]
        let fn_sig = self.tcx.fn_sig(method);