protected override async Task OnStart(IMessageSession session)
 {
     using (var connection = await connectionFactory())
     {
         await persister.PurgeItems(connection, null, CancellationToken.None).ConfigureAwait(false);
     }
 }
 protected override Task OnStart(IMessageSession session)
 {
     persister.PurgeItems();
     return(Task.CompletedTask);
 }