public function getSheetByName($pName = '')
    {
        $worksheetCount = count($this->_workSheetCollection);
        for ($i = 0; $i < $worksheetCount; ++$i) {
            if ($this->_workSheetCollection[$i]->getTitle() === $pName) {
                return $this->_workSheetCollection[$i];
            }
        }

        return NULL;
    }