/// <summary>
        /// Exports the tree.
        /// </summary>
        /// <param name="root">The root element.</param>
        /// <param name="includeRoot">if set to <c>true</c> the also export the root element, else
        /// if set to <c>false</c>, then the children are exported.</param>
        public void ExportTree(EATree root, bool includeRoot)
        {
            m_XmlDocument = new XmlDocument()
            {
                XmlResolver = null
            };
            XmlDocumentFragment xmlFragment = m_XmlDocument.CreateDocumentFragment();

            DocBookFormat format = new DocBookFormat();

            if (includeRoot)
            {
                XmlNode xnode = ExportElement(root, format);
                xmlFragment.AppendChild(xnode);
            }
            else
            {
                foreach (EATree child in root.Children)
                {
                    XmlNode xnode = ExportElement(child, format);
                    xmlFragment.AppendChild(xnode);
                }
            }
            xmlFragment.WriteContentTo(m_XmlWriter);
        }