I believe this is due to the `onError` call [here](https://github.com/goto-bus-stop/dart-event-source/blob/d4d67ca78a9166016d2205369c9cba71a38452e2/lib/event_source.dart#L137-L138). The `(_)` error is: `HttpException: Connection closed while receiving data, uri = http://127.0.0.1/redacted`.