public function allDrawings(PHPExcel $pPHPExcel = null)
    {
        // Get an array of all drawings
        $aDrawings    = array();

        // Loop through PHPExcel
        $sheetCount = $pPHPExcel->getSheetCount();
        for ($i = 0; $i < $sheetCount; ++$i) {
            // Loop through images and add to array
            $iterator = $pPHPExcel->getSheet($i)->getDrawingCollection()->getIterator();
            while ($iterator->valid()) {
                $aDrawings[] = $iterator->current();

                  $iterator->next();
            }
        }

        return $aDrawings;
    }