private boolean isS3MultipartUploadCompleteRequest(RestRequest restRequest) {
      return S3BaseHandler.isMultipartCompleteUploadRequest(restRequest);
    }
@param restRequest incoming {@link RestRequest}
@return {@code true} if this is a S3 multipart completee request
ambry-frontend/src/main/java/com/github/ambry/frontend/AmbryIdConverterFactory.java