code: function (oNode) {
  			var iSelectedNodesCount = 0,
  				oChildNode;
  
  			for (var i = 0; i < oNode.nodes.length; i++) {
  				oChildNode = oNode.nodes[i];
  				if (oChildNode.nodes.length) {
  					oChildNode.selected = this.isNodeSelected(oChildNode);
  				}
  				if (oChildNode.selected) {
  					iSelectedNodesCount++;
  				}
  			}
  
  			return iSelectedNodesCount === oNode.nodes.length;
  		}
docs: Checks and update the tree model based on selected child nodes.
  @param oNode The tree to be updated
  @returns {boolean} The selected of the node.