private void appendNode(StringBuilder buf, DefaultMutableTreeNode node, String lineSeparator, String indent) {
    buf.append(indent);
    final String childIndent;
    if (node.getParent() != null) {
      childIndent = indent + "    ";
      appendNodeText(buf, node, lineSeparator);
    }
    else {
      childIndent = indent;
    }

    Enumeration enumeration = node.children();
    while (enumeration.hasMoreElements()) {
      DefaultMutableTreeNode child = (DefaultMutableTreeNode)enumeration.nextElement();
      appendNode(buf, child, lineSeparator, childIndent);
    }
  }
private void appendNode(StringBuilder buf, DefaultMutableTreeNode node, String lineSeparator, String indent)