/// <summary>
        /// Select all nodes within the selection box
        /// </summary>
        private void SelectNodes()
        {
            if (!CanSelectNodes)
            {
                return;
            }

            IEnumerable <Node> nodesInRect =
                NodeEditor.GetNodesInRect(selectionRect, AllowOverlaps);

            foreach (Node node in nodesInRect)
            {
                node.Select();
            }
        }