{"ast_node_type":"variable","tokens":[{"end":85,"kind":"keyword","start":0,"text":"let"}]}
                let fty = self.tcx.fn_sig(method.def_id).instantiate(self.tcx, args);
                let args = self.fresh_args_for_item(self.span, method.def_id);
                let fty = self.instantiate_binder_with_fresh_vars(