private function renderLine()
    {
        $output = [];
        $output[] = $this->charCross;
        if (count($this->columns) > 0) {
            for ($columnNumber = 0; $columnNumber < count($this->columns); $columnNumber++) {
                $output[] = $this->renderCell($columnNumber, $this->charHorizontal, $this->charHorizontal);
                $output[] = $this->charCross;
            }
        }
        return implode('', $output);
    }