intersect function
Creates an list of unique values that are included in all given arrays Example
final lists = [
[1, 2, 3],
[2, 4, 5],
[2, 8, 9]
];
intersect(lists);
// Returns [2]
Implementation
intersect(List<List> arrays) {
return arrays.fold<Set>(
arrays.first.toSet(), (a, b) => a.intersection(b.toSet()));
}