Copy data class with recursive children

node.dart

class Node {
  Node(this.title, [this.children = const []]);

  final String title;
  final List<Node> children;
}

Node copy(Node n) {
  // create new object with data from old object
  return Node(
    n.title,
    // for each child map with copy recursively to create new list of children
    n.children.map(copy).toList(),
  );
}

main() {
  final oldList = [
    Node('A', [Node('B'), Node('C')]),
    Node('D', [
      Node('E', [Node('F')])
    ]),
  ];
  final newList = oldList.map(copy).toList();
  oldList[1].children[0].children.clear();
  print(oldList[1].children[0].children);
  print(newList[1].children[0].children);
}