public override void UpdateDatabaseAfterUpdateSchema()
 {
     base.UpdateDatabaseAfterUpdateSchema();
     if (!ObjectSpace.Any <CronExpression>())
     {
         var expressions = new[] { nameof(Cron.Minutely), nameof(Cron.Hourly), nameof(Cron.Daily), nameof(Cron.Monthly), nameof(Cron.Yearly) }
         .Select(s => (name: s, value: $"{typeof(Cron).Method(s,Type.EmptyTypes,Flags.StaticPublic).Call(null)}"));
         foreach (var expression in expressions)
         {
             var cronExpression = ObjectSpace.CreateObject <CronExpression>();
             cronExpression.Name       = expression.name;
             cronExpression.Expression = expression.value;
         }
         ObjectSpace.CommitChanges();
     }
 }