/// <summary>
        /// 添加节点
        /// </summary>
        public FSMStateNode AddNode(Vector2 position)
        {
            var node = new FSMStateNode(this);

            node.SetPosition(new Rect(position, defaultNodeSize));
            node.RefreshExpandedState();
            node.RefreshPorts();

            AddElement(node);
            return(node);
        }