RuntimeException rt = new RuntimeException("Attempt to remove subtasks while enum is active"); rt.printStackTrace();
logger.error("Attempt to remove subtasks while enum is active", new Throwable());
  public synchronized List clearSubTasks() {    if (walkingSubtasks > 0) {      RuntimeException rt = 	new RuntimeException("Attempt to remove subtasks while enum is active");      rt.printStackTrace();    }    ArrayList l = new ArrayList(subtasks);    subtasks.removeAllElements();    changedSubtasks.clear();    return l;  }