assign method

Implementation

@override
void assign(TPersistent? source) {
  if (source is TCollection) {
    beginUpdate();
    try {
      clear();
      for (var i = 0; i < source.count; i++) {
        add().assign(source.getItem(i));
      }
    } finally {
      endUpdate();
    }
    return;
  }
  super.assign(source);
}