private async Task <CollectionPrepareResult> CheckFullCollectionTransitAsync(ITextStatusNotifier progress, CancellationToken token)
{
_logger.Debug("Detected full transit for collection {Collection}", _collectionName);
progress.Status = "Removing documents from destination...";
await _destination.DeleteAllDocumentsAsync(token);
progress.Status = "Counting documents...";
var count = await _source.CountAllAsync(token);
return(new CollectionPrepareResult(SourceFilter.Empty, count));
}