public virtual void Save(XmlDocument doc, XmlElement xe)
{
this.SaveAttribute(doc, xe);
for (int i = 0; i < m_Children.Count; i++)
{
BTNode node = m_Children[i];
XmlElement child = doc.CreateElement(node.GetType().Name);
node.Save(doc, child);
xe.AppendChild(child);
}
}