private async Task StartCopyFromBlob(long taskId, IStorageBlobManagement destChannel, CloudBlob srcBlob, CloudBlob destBlob)
 {
     try
     {
         await StartCopyFromUri(taskId, destChannel, srcBlob.GenerateUriWithCredentials(), destBlob);
     }
     catch (StorageException ex)
     {
         if (0 == string.Compare(ex.Message, BlobTypeMismatch, StringComparison.OrdinalIgnoreCase))
         {
             // Current use error message to decide whether it caused by blob type mismatch,
             // We should ask xscl to expose an error code for this..
             // Opened workitem 1487579 to track this.
             throw new InvalidOperationException(Resources.DestinationBlobTypeNotMatch);
         }
         else
         {
             throw;
         }
     }
 }