@Override
public void insert(MutableTreeNode newChild, int childIndex)    {
    super.insert(newChild, childIndex);
    Collections.sort(this.children, nodeComparator);
}
 
protected Comparator nodeComparator = new Comparator () {
    @Override
    public int compare(Object o1, Object o2) {
        return o1.toString().compareToIgnoreCase(o2.toString());
    }
 
    @Override
    @SuppressWarnings("EqualsWhichDoesntCheckParameterClass")
    public boolean equals(Object obj)    {
        return false;
    }
 
    @Override
    public int hashCode() {
        int hash = 7;
        return hash;
    }
};