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If I can't do instanceof T in Java (due to type erasure), then how do I write a generic tree node? setUserObject() accepts Object, not T. Do I have no better choice than making clients pass Class literals?

public class ItemTreeNode<T> extends DefaultMutableTreeNode {

    public ItemTreeNode(T userObject) {
        super(userObject);
    }

    @Override
    @SuppressWarnings("unchecked")
    public void setUserObject(Object userObject) {
        super.setUserObject((T) userObject); // would throw ClassCastException if it's not T
    }

    @Override
    @SuppressWarnings("unchecked")
    public T getUserObject() {
        return (T) super.getUserObject();
    }
}