code: @Test(groups = {SAMPLES})
      public void getDE1BillingStatsGroupedByServers() {
          List<BillingStatsEntry> stats = statisticsService
              .billingStats()
              .forDataCenters(
                  new DataCenterFilter()
                      .dataCenters(DE_FRANKFURT)
              )
              .groupByServer();
  
          assertNotNull(stats);
      }
docs: Step 3. App query billing statistics grouped by servers within DE1 Datacenter