linesIndexed method
Implementation
Future<Map<int, String>> linesIndexed() async {
var lines = await openRead()
.map(utf8.decode)
.transform(const LineSplitter())
.toList();
Map<int, String> map = {};
var i = 0;
for (var line in lines) {
map[i] = line;
i += 1;
}
return map;
}