} else if (o instanceof DMTNArray) { return new MyArrayTransferable((DMTNArray)o);
  public Transferable makeDraggableObject(Object o) {    Transferable tran = null;    if (o instanceof DefaultMutableTreeNode) {      DefaultMutableTreeNode node = (DefaultMutableTreeNode) o;      return new MyTransferable(node);    }    throw new IllegalArgumentException("Not a DefaultMutableTreeNode");  }