private function getTableCellWidth($total, $cells)
    {
        $widths = [];
        if (is_int($cells)) {
            $width = floor($total/$cells);
            for ($i=0; $i<$cells; ++$i) {
                $widths[] = $width;
            }
        }
        else if (is_array($cells)){
            $width = floor($total/count($cells));
            foreach ($cells as $i) {
                $widths[$i] = $width;
            }
        }
        return $widths;
    }