Printing 当我想在flatter中打印列时，它不会在列之间提供任何空格，如下图所示

import 'package:esc_pos_printer/esc_pos_printer.dart';
import 'package:esc_pos_utils/esc_pos_utils.dart';

printItem() async {
  const PaperSize paper = PaperSize.mm80;

  final profile = await CapabilityProfile.load();
  final printer = NetworkPrinter(paper, profile, spaceBetweenRows: 30);

  final PosPrintResult res =
      await printer.connect('192.168.100.30', port: 9100);

  if (res == PosPrintResult.success) {
    printer.row([
      PosColumn(
        text: 'col3',
        width: 3,
        styles: PosStyles(align: PosAlign.center, underline: true),
      ),
      PosColumn(
        text: 'col6',
        width: 6,
        styles: PosStyles(align: PosAlign.center, underline: true),
      ),
      PosColumn(
        text: 'col3',
        width: 3,
        styles: PosStyles(align: PosAlign.center, underline: true),
      ),
    ]);
    printer.row([
      PosColumn(
        text: 'col3',
        width: 3,
        styles: PosStyles(align: PosAlign.center, underline: true),
      ),
      PosColumn(
        text: 'col6',
        width: 6,
        styles: PosStyles(align: PosAlign.center, underline: true),
      ),
      PosColumn(
        text: 'col3',
        width: 3,
        styles: PosStyles(align: PosAlign.center, underline: true),
      ),
    ]);
    printer.feed(2);
    printer.cut();
    printer.disconnect();
    print('Print result: ${res.msg}');
  }
}