��助文本
  chart.guide().html({
    position: [ '50%', '50%' ],
    html: '<div style="color:#8c8c8c;font-size: 14px;text-align: center;width: 10em;">监控主机<br><span style="color:#8c8c8c;font-size:20px">[[${totalSystemInfoSize}]]</span>台</div>',
    alignX: 'middle',
    alignY: 'middle'
  });
  const interval = chart.intervalStack()
          .position('percent')
          .color('item')
          .label('count', {
            formatter: (val, item) => {
            return item.point.item + ': '