public override void Assign(RepositoryItem item)
        {
            BeginUpdate();

            try
            {
                base.Assign(item);
                RepositoryItemBlockImageComboBoxEdit source = item as RepositoryItemBlockImageComboBoxEdit;
                if (source == null)
                {
                    return;
                }
            }
            finally
            {
                EndUpdate();
            }
        }
 static BlockImageComboBoxEdit()
 {
     RepositoryItemBlockImageComboBoxEdit.RegisterBlockImageComboBoxEdit();
 }