// Create selector.
DateRange range = new DateRange(TestUtils.firstDayOfMonth(), TestUtils.today());
InfoSelector selector = new InfoSelector("CampaignService", "mutate", Operator.ADD, range,
new String[] {clientId}, ApiUsageType.UNIT_COUNT_FOR_CLIENTS);
ApiUsageInfo apiUsageInfo = service.get(selector);
assertNotNull(apiUsageInfo.getApiUsageRecords());
assertEquals(clientId, apiUsageInfo.getApiUsageRecords()[0].getClientEmail());
assertNotNull(apiUsageInfo.getApiUsageRecords()[0].getCost());
}