void makeChildren() {
      children = new ArrayList<>();

      if (var instanceof Structure) {
        Structure s = (Structure) var;
        List vars = s.getVariables();
        for (int i = 0; i < vars.size(); i++)
          children.add(new VariableNode(this, (VariableIF) vars.get(i)));
      }

      if (debugTree) System.out.println("children=" + var.getShortName() + " ");
    }
 public String toString() {
   return var.getShortName();
 }
 public int getIndex(TreeNode child) {
   if (debugTree) System.out.println("getIndex=" + var.getShortName() + " " + child);
   return children.indexOf(child);
 }
 VariableNode(TreeNode parent, VariableIF var) {
   this.parent = parent;
   this.var = var;
   if (debugTree) System.out.println("new var=" + var.getShortName() + " ");
   // firePropertyChangeEvent(new PropertyChangeEvent(this, "TreeNode", null, var));
 }