public void RemoveCell(CellValueRecordInterface cell){if (cell == null){throw new ArgumentException("cell must not be null");}int row = cell.Row;if (row >= records.Length){throw new Exception("cell row is out of range");}CellValueRecordInterface[] rowCells = records[row];if (rowCells == null){throw new Exception("cell row is already empty");}int column = cell.Column;if (column >= rowCells.Length){throw new Exception("cell column is out of range");}rowCells[column] = null;}