text: public bool ContainsCell(int rowIndex, int columnIndex){for (int i = _rectangleGroups.Count - 1; i >= 0; i--){BlankCellRectangleGroup bcrg = (BlankCellRectangleGroup)_rectangleGroups[i];if (bcrg.ContainsCell(rowIndex, columnIndex)){return true;}}if (_currentRectangleGroup != null && _currentRectangleGroup.ContainsCell(rowIndex, columnIndex)){return true;}if (_currentRowIndex != -1 && _currentRowIndex == rowIndex){if (_firstColumnIndex <= columnIndex && columnIndex <= _lastColumnIndex){return true;}}return false;}