private void DeleteExtractionRequestFromCollection(DataRetrievalRequest dataRetrievalRequest)
        {
            if (DataRetrievalRequests.Count == 0)
            {
                throw new CollectionEmptyException();
            }
            if (dataRetrievalRequest == null)
            {
                throw new ArgumentNullException("dataRetrievalRequest", "Cannot be null");
            }

            DataRetrievalRequests.Remove(dataRetrievalRequest); //not concerned about successful removal, no need to interpret return bool.
        }
 protected void AddNewEmptyExtractionRequest()
 {
     DataRetrievalRequests.Add(new DataRetrievalRequest());
 }