/// <summary>
/// 父节点转化为Layer，即层级数(用于保存)
/// </summary>
/// <param name="parent"></param>
/// <param name="layer"></param>
/// <returns></returns>
public int ParentToLayer(NodeModifier parent, int layer = 0)
{
layer++;
if (this == parent)
{
return(layer);
}
if (_lastNode == null)
{
return(0);
}
return(_lastNode.ParentToLayer(parent, layer));
}
