readAsBytes method
Reads the entire file contents as a list of bytes.
Returns a Future<Uint8List>
that completes with the list of bytes that
is the contents of the file.
Implementation
@override
Future<Uint8List> readAsBytes() => openRead().fold(
<int>[],
(List<int> previous, List<int> element) => previous
..addAll(element)).then((List<int> list) => Uint8List.fromList(list));