protected function getLines(Matrix $mA)
    {
        $lines = array();
        $data = $mA->toArray();
        $rows = $mA->rows();
        $cols = $mA->columns();
        for ($row = 0; $row < $rows; $row++) {
            $line = '';
            for ($col = 0; $col < $cols; $col++) {
                $line .= $data[$row][$col];
            }
            $lines[$row] = $line;
        }

        return $lines;
    }