4.0版本在angular中多标题报错

描述:当前是关于Echarts图表中的 柱状图 示例。
 
            option = {
      title: [{
        gridIndex: 0,
        text: '测试1',
        subtext: '总计 ',
        x: '25%',
        textAlign: 'center'
      },{
        gridIndex: 0,
        text: '测试2',
        subtext: '总计 ',
        x: '50%',
        textAlign: 'center'
      }],
      tooltip: {},
      xAxis: [
        { type: 'category', gridIndex: 0, data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'] },
        { type: 'category', gridIndex: 1, data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'] }
      ],
      yAxis: [
        { gridIndex: 0 },
        { gridIndex: 1 }
      ],
      grid: [{
        top: 50,
        width: '100%',
        bottom: '45%',
        left: 10,
        containLabel: true
      }, {
        top: '55%',
        width: '100%',
        bottom: 0,
        left: 10,
        containLabel: true
      }],
      series: [
        {
          name: '直接访问',
          type: 'bar',
          xAxisIndex: 0,
          yAxisIndex: 0,
          data: [86.5, 92.1, 85.7, 83.1]

        },
        {
          name: '间接访问',
          type: 'bar',
          xAxisIndex: 1,
          yAxisIndex: 1,
          data: [86.5, 92.1, 85.7, 83.1]
        }
      ]
};