insert method

@override void insert(int index, Object data, Style? style)

Implementation

@override
void insert(int index, Object data, Style? style) {
  assert(index == 0 || (index > 0 && index < length));

  if (isNotEmpty) {
    final child = queryChild(index, false);
    child.node!.insert(child.offset, data, style);
    return;
  }

  // empty
  assert(index == 0);
  final node = defaultChild;
  add(node);
  node?.insert(index, data, style);
}