public void SetBinop(PBinop node)
        {
            if (_binop_ != null)
            {
                _binop_.Parent(null);
            }

            if (node != null)
            {
                if (node.Parent() != null)
                {
                    node.Parent().RemoveChild(node);
                }

                node.Parent(this);
            }

            _binop_ = node;
        }
        public void SetOperator(PBinop node)
        {
            if (_operator_ != null)
            {
                _operator_.Parent(null);
            }

            if (node != null)
            {
                if (node.Parent() != null)
                {
                    node.Parent().RemoveChild(node);
                }

                node.Parent(this);
            }

            _operator_ = node;
        }