private void addToRequestQueue(List<RequestInfo> requestInfos) {
    Timer.Context timer = routerMetrics.addToQueueTime.time();
    for (RequestInfo requestInfo : requestInfos) {
      QuotaResource quotaResource = null;
      if (requestInfo.getChargeable() != null) {
        quotaResource = requestInfo.getChargeable().getQuotaResource();
      }
      if (quotaResource == null) {
        routerMetrics.requestsWithUnknownQuotaResourceRate.mark();
        quotaResource = UNKNOWN_QUOTA_RESOURCE;
      }
      getRequestQueue(requestInfo.getChargeable().getQuotaMethod()).putIfAbsent(quotaResource, new LinkedList<>());
      getRequestQueue(requestInfo.getChargeable().getQuotaMethod()).get(quotaResource).add(requestInfo);
    }
    timer.stop();
  }
Add the specified {@link List} of {@link RequestInfo}s to the request queue.
@param requestInfos {@link List} of {@link RequestInfo} objects.
ambry-router/src/main/java/com/github/ambry/router/QuotaAwareOperationController.java