apex怎么取消已经提交的approval request呢

大概这种应用场景不多，文档里竟然没有找到介绍。

终于在谷歌老师的帮助下，获得了如下神码(经过我的二次整理优化)：

List<Approval.ProcessWorkitemRequest> requestList = new List<Approval.ProcessWorkitemRequest> ();
                for (ProcessInstanceWorkitem workItem : [ 
                        SELECT Id
                        FROM ProcessInstanceWorkitem 
                        WHERE ProcessInstance.TargetObjectId IN :idListToRecallList
                        AND ProcessInstance.Status = 'Pending' 
                    ]) {

                    Approval.ProcessWorkitemRequest workItemRequest = new Approval.ProcessWorkitemRequest();  
                    workItemRequest.setAction('Removed');
                    workItemRequest.setWorkItemId(workItem.Id);
                    requestList.add(workItemRequest);

                }

                List<Approval.ProcessResult> result = Approval.process(requestList);