cb.aggregation().setRequestedAt_DateHistogram(SearchLogPager.LOG_TYPE_SEARCH_COUNT_HOUR, op -> {
                    op.calendarInterval(DateHistogramInterval.HOUR);
                    op.minDocCount(0);
                    op.order(BucketOrder.key(true));
                }, null);
            });
            final Histogram agg = list.getAggregations().get(SearchLogPager.LOG_TYPE_SEARCH_COUNT_HOUR);