private void AddtoDgv(CalendarItem item)
        {
            if (_items.All(x => x.Id != item.Id))
            {
                _items.Add(item.Map());
                return;
            }

            if (item.SyncStatus.CalenadCalendarItemStatus == CalendarItemStatus.Updated)
            {
                var oldItem = _items.FirstOrDefault(x => x.Id == item.Id);
                if (oldItem != null)
                {
                    oldItem = item.Map();
                }
            }
            if (item.SyncStatus.CalenadCalendarItemStatus == CalendarItemStatus.New)
            {
                _items.Add(item.Map());
            }
            if (item.SyncStatus.CalenadCalendarItemStatus == CalendarItemStatus.Deleted)
            {
                var oldItem = _items.FirstOrDefault(x => x.Id == item.Id);
                if (oldItem != null)
                {
                    _items.Remove(oldItem);
                }
            }
        }