private void SoftDeleting()
        {
            ChangeTracker.DetectChanges();
            // fix trackable entities
            var markedAsDeleted = ChangeTracker.Entries<ISoftDeletable>().Where(x => x.State == EntityState.Deleted);

            foreach (var item in markedAsDeleted)
            {
                // Set the entity to unchanged (if we mark the whole entity as Modified, every field gets sent to Db as an update)
                item.State = EntityState.Unchanged;
                // Only update the IsDeleted flag - only this will get sent to the Db
                item.Entity.IsDeleted = true;
            }
        }