class CollapseExpandListener implements TreeListener{
                     TreeViewer sourceTreeViewer;
	CollapseExpandListener(TreeViewer tree){
		sourceTreeViewer = tree;
	}
	@Override
	public void treeCollapsed(TreeEvent e) {
                              ISecTreeNode node = ((ISecTreeNode)e.item.getData())
	
HOW DIO I REMOVE THE CAHCNED CHILDREN from node????
	}
	@Override
	public void treeExpanded(TreeEvent e) {
                               //NO-OP
                     }
}