unionList<T> function
Get new elements from input
Implementation
List<T> unionList<T>(Iterable<T> original, Iterable<T> input) {
List<T> l1 = List.from(original);
List<T> l2 = List.from(input);
List<T> result = List.from(l1);
for (T element in l2) {
if (!result.contains(element)) {
result.add(element);
}
}
return result;
}