range method

Channels range(
  1. int start, [
  2. int? end
])

Implementation

Channels range(int start, [int? end]) {
  final res = list.map((e) {
    if (end != null && e.length < end) return <double>[];
    return e.sublist(start, end);
  }).toList();
  return Channels.fromList(res);
}