private QuotaSource getQuotaSourceMember(AmbryQuotaManager ambryQuotaManager) throws Exception {
    Field field = ambryQuotaManager.getClass().getDeclaredField("quotaEnforcers");
    field.setAccessible(true);
    return new ArrayList<>((Set<QuotaEnforcer>) field.get(ambryQuotaManager)).get(0).getQuotaSource();
  }
Gets the first {@link QuotaSource} from the {@link AmbryQuotaManager} object via reflection.
@param ambryQuotaManager {@link AmbryQuotaManager} object.
@return QuotaSource object.
@throws Exception
ambry-quota/src/test/java/com/github/ambry/quota/AmbryQuotaManagerUpdateNotificationTest.java