private void AddOperationComboBox()
        {
            var items = GridComboItem.CreateForEnum <GroupOperation>().ToList();
            var cmn   = Adapter.GetColumn(f => f.GroupOperation);

            Adapter.AddComboBox(cmn, items);
        }
        private void BuildStringOperationList()
        {
            var operations = new[] { GroupOperation.Max, GroupOperation.Min, GroupOperation.Mode };

            _stringOperations = GridComboItem.CreateForEnum(operations).ToList();
        }