public void Save(string objectId, string collectionId, string content)
 {
     try
     {
         var filepath = Path.Combine(storageDirectoryAbsolutePath, collectionId, objectId + ".json");
         TransactionalFileOps.SaveFileContents(filepath, content);
     }
     catch (Exception exception)
     {
         throw new PersistenceException("Flat File saving failed. See inner exception for details", exception);
     }
 }