code: public List<String> getNotifierSpecs(Long taskId, String outcome) throws ObserverException {
          TaskTemplate taskVO = TaskTemplateCache.getTaskTemplate(taskId);
          if (taskVO != null) {
              String noticesAttr = taskVO.getAttribute(TaskAttributeConstant.NOTICES);
              if (!StringHelper.isEmpty(noticesAttr) && !"$DefaultNotices".equals(noticesAttr)) {
                  return parseNoticiesAttr(noticesAttr, outcome);
              }
          }
          return null;
      }
docs: Returns a list of notifier class name and template name pairs, delimited by colon
  @param taskId
  @param outcome
  @return the registered notifier or null if not found