/// <summary>
        /// Fires before inserting tree node to the tree. Performs the additional actions before the tree node is inserted.
        /// </summary>
        /// <param name="treeNodeObj">TreeNode object to insert to tree</param>
        /// <param name="parentNodeId">Parent node ID.</param>
        /// <param name="tree">TreeProvider object to use</param>
        public override void OnBeforeInsert(object treeNodeObj, int parentNodeId, object tree)
        {
            // To change a Document Type's default template dynamically when creating it, 
            // you will need to use the custom tree node handler (OnBeforeInsert method/event).  
            // Then change there DocumentPageTemplateID of available TreeNode objects to point to 
            // some page templage (table CMS_PageTemplate -> Column PageTemplateID).  
            // In this custom tree node handler you can check if the TreeNode object is of some 
            // specific class (in this case document type) and if so, then change the page template 
            // for document.  You can find DocumentPageTemplateID in the CMS_Document table.
            // PageTemplateID	PageTemplateDisplayName
            // 25	Product multicolumn view

            TreeNode treeNode = (TreeNode)treeNodeObj;

            if (treeNode.NodeClassName.ToLower() == "cms.cellphone")
            {
                treeNode.DocumentPageTemplateID = 25;
            }
        }