@Override
  public QuotaEnforcer getQuotaEnforcer() {
    return rejectingQuotaEnforcer;
  }
Constructor for {@link AmbryCUQuotaSourceFactory}.
@param quotaConfig {@link QuotaConfig} object.
@param quotaSource {@link QuotaSource} object.
@param accountStatsStore {@link AccountStatsStore} object.
@param quotaMetrics {@link QuotaMetrics} object.
ambry-router/src/test/java/com/github/ambry/router/RejectingQuotaEnforcerFactory.java