code: 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];
      }
docs: Get data validation.
  
  @param string $pCellCoordinate Cell coordinate to get data validation for, eg: 'A1'
  
  @return DataValidation