 		}
 	}
 	
-	fileprivate var indentationLevel: Int {
+	open var indentationLevel: Int {
 		return parent?.isViewable == true ? parent!.indentationLevel + 1 : parent?.indentationLevel ?? 0
 	}
 	

		
	}
	
	private weak var _treeController: TreeController?
	fileprivate var isViewable: Bool {
		return cellIdentifier != nil

		}
	}
	
	open func loadChildren() {
	}
	
	open func update(from node: TreeNode) {
		isExpanded = node.isExpanded
		estimatedHeight = node.estimatedHeight
		
		if let to = _children, let from = node._children {
