code: private Transition findTaskActionWorkTransition(ProcessInstance parentInstance,
              ActivityInstance activityInstance, String taskAction) {
          if (taskAction == null)
              return null;
  
          Process processVO = getProcessDefinition(parentInstance);
          Transition workTransVO = processVO.getTransition(activityInstance.getActivityId(), EventType.RESUME, taskAction);
          if (workTransVO == null) {
              // try upper case
              workTransVO = processVO.getTransition(activityInstance.getActivityId(), EventType.RESUME, taskAction.toUpperCase());
          }
          if (workTransVO == null) {
              workTransVO = processVO.getTransition(activityInstance.getActivityId(), EventType.FINISH, taskAction);
          }
          return workTransVO;
      }
docs: Look up the appropriate work transition for an embedded exception handling subprocess.
  @param parentInstance the parent process
  @param activityInstance the activity in the main process
  @param taskAction the selected task action
  @return the matching work transition, if found