docs: protected void performStart(CmmnActivityExecution execution) {
      CmmnActivity activity = execution.getActivity();
      List<CmmnActivity> childActivities = activity.getActivities();
  
      if (childActivities != null && !childActivities.isEmpty()) {
        List<CmmnExecution> children = execution.createChildExecutions(childActivities);
        execution.createSentryParts();
        execution.triggerChildExecutionsLifecycle(children);
  
  
        if (execution.isActive()) {
          execution.fireIfOnlySentryParts();
          // if "autoComplete == true" and there are no
          // required nor active child activities,
          // then the stage will be completed.
          if (execution.isActive()) {
            checkAndCompleteCaseExecution(execution);
          }
        }
  
      } else {
        execution.complete();
      }
    }