}
    public void removeTreeNode(Array a) throws Exception {        javax.swing.tree.DefaultMutableTreeNode tn = getJavaTreeNode();        if (tn != null) {                if (a != null) {                // It is bad coding style to use instanceof.                // However, since this method is a temporary solution anyway,                // it seems the simplest way to work with instanceof here.                // This check had to be inserted because signal items have                // children that are not child tree nodes of that signal.                // Alternative:                // if (tn.isNodeChild(i.getJavaTreeNode())) {                if ((a instanceof Signal) == false) {                    tn.remove(a.getJavaTreeNode());                }            } else {                    java.lang.System.out.println("DEBUG: Could not remove java tree node. The array is null.");            }        } else {            throw new Exception("Could not remove java tree node. The java tree node is null.");        }    }