internal override void ExecuteInstanceImp(ISession session)
{
//创建新任务节点
var workItem = (WorkItem)WorkItemNodeFactory.CreateNewNode(base.BackwardContext.BackwardToTaskActivity);
workItem.CreateActivityTaskAndTransitionInstances(base.BackwardContext.ProcessInstance,
base.BackwardContext.FromActivityInstance,
base.BackwardContext.BackwardToTargetTransition,
TransitionTypeEnum.Withdrawed,
base.ActivityResource,
session);
//更新当前办理节点的状态（从准备或运行状态更新为退回状态）
var aim = new ActivityInstanceManager();
aim.Reject(base.BackwardContext.FromActivityInstance.ActivityInstanceGUID, base.ActivityResource.LogonUser, session);
//构造回调函数需要的数据
base.WfExecutedResult = WfExecutedResult.Success();
}