public void setParentModel(CompoundModel parent) {
super.setParentModel(parent);
// if a parent of a model is set as null, do not update ClusterManager
if (parent != null) {
setClusterManager(parent.getClusterManager());
}
}
public void undo() {
parent.addChild(child);
child.setParentModel(parent);
restoreConnections();
}