{"ast_node_type":"other","tokens":[{"end":26,"kind":"keyword","start":0,"text":".map_err(|e|"}]}
            .map_err(|e| {
            .map(|infer_ok| self.register_infer_ok_obligations(infer_ok))
                self.err_ctxt().report_mismatched_types(cause, self.param_env, expected, actual, e)