protected virtual Task<IEnumerable<CatalogItemBatch>> CreateBatches(IEnumerable<CatalogItem> catalogItems)
{
var batches = catalogItems
.GroupBy(item => item.CommitTimeStamp)
.OrderBy(group => group.Key)
.Select(group => new CatalogItemBatch(group.Key, group));
return Task.FromResult(batches);
}