{"ast_node_type":"variable","tokens":[{"end":65,"kind":"keyword","start":0,"text":"let"}]}
        let generic_param = generics.type_param(param, self.tcx);
        let generics = self.tcx.generics_of(self.body_id);
        if let ty::GenericParamDefKind::Type { synthetic: true, .. } = generic_param.kind {