docs: public static <T extends Enum<T>> OperationStatistic<T> findOperationStatisticOnChildren(Object context, Class<T> type, String statName) {
      @SuppressWarnings("unchecked")
      Query query = queryBuilder()
        .children()
        .filter(context(attributes(Matchers.allOf(hasAttribute("name", statName), hasAttribute("type", type)))))
        .build();
  
      Set<TreeNode> result = query.execute(Collections.singleton(ContextManager.nodeFor(context)));
      if (result.size() > 1) {
        throw new RuntimeException("result must be unique");
      }
      if (result.isEmpty()) {
        throw new RuntimeException("result must not be null");
      }
      @SuppressWarnings("unchecked")
      OperationStatistic<T> statistic = (OperationStatistic<T>) result.iterator().next().getContext().attributes().get("this");
      return statistic;
    }