BaseTreeModel + setChildren = ConcurrentModificationException

[fother]

public static void main(final String[] args) {

final BaseTreeModel model1 = new BaseTreeModel();
model1.add(new BaseTreeModel());
model1.add(new BaseTreeModel());
model1.add(new BaseTreeModel());
model1.add(new BaseTreeModel());

List<ModelData> children = model1.getChildren();

final BaseTreeModel model2 = new BaseTreeModel();
model2.setChildren(children);

System.out.println(model2.getChildCount());

}




Exception in thread "main" java.util.ConcurrentModificationException
at java.util.AbstractList$Itr.checkForComodification(Unknown Source)
at java.util.AbstractList$Itr.next(Unknown Source)
at com.extjs.gxt.ui.client.data.BaseTreeModel.setChildren(BaseTreeModel.java:178)