rotate<T> method
Implementation
List<T> rotate<T>(int amount, bool isRight) {
List<T> target = List.from(this);
if (isRight) {
for (var i = 0; i < amount; i++) {
target.insert(0, target.removeLast());
}
} else {
for (var i = 0; i < amount; i++) {
target.add(target.removeAt(0));
}
}
return target;
}