public function allBorders(PHPExcel $pPHPExcel = null)
    {
        // Get an array of unique borders
        $aBorders = array();
        $aStyles = $this->allStyles($pPHPExcel);

        foreach ($aStyles as $style) {
            if (!array_key_exists($style->getBorders()->getHashCode(), $aBorders)) {
                $aBorders[ $style->getBorders()->getHashCode() ] = $style->getBorders();
            }
        }

        return $aBorders;
    }