public function getDataValidation($pCellCoordinate)
    {
        // return data validation if we already have one
        if (isset($this->dataValidationCollection[$pCellCoordinate])) {
            return $this->dataValidationCollection[$pCellCoordinate];
        }

        // else create data validation
        $this->dataValidationCollection[$pCellCoordinate] = new DataValidation();

        return $this->dataValidationCollection[$pCellCoordinate];
    }