Collects the data of this stream in a List.
Source
Future<List<T>> toList() { List<T> result = <T>[]; _Future<List<T>> future = new _Future<List<T>>(); this.listen( (T data) { result.add(data); }, onError: future._completeError, onDone: () { future._complete(result); }, cancelOnError: true); return future; }