Another reason is that when the user is creating a connection, the connection EditPart doesn't exist, so the node must be able to show feedback on its own.
另一个原因是，当用户创建连接时，连接EditPart是不存在的，因此节点必须能够自己显示反馈。
3
Aiming at the volatility of demand in the supply chain, the feedback controller was used to maintain product inventory of each node, so that the supply chain reached stabilization.