@Override
  public Map<String, Double> calculateRequestCost(RestRequest restRequest, RestResponseChannel restResponseChannel,
      BlobInfo blobInfo) {
    Map<String, Double> costMap = new HashMap<>();
    costMap.put(QuotaUtils.getCUQuotaName(restRequest).name(),
        calculateCapacityUnitCost(restRequest, restResponseChannel, blobInfo));
    costMap.put(QuotaName.STORAGE_IN_GB.name(),
        QuotaUtils.calculateStorageCost(restRequest, restRequest.getBlobBytesReceived()));
    return costMap;
  }
Simple {@link AmbryCostModelPolicy} implementation that calculates CU costs in 4MB units and Storage cost in GB units.
ambry-frontend/src/main/java/com/github/ambry/frontend/SimpleAmbryCostModelPolicy.java