ie11 不支持 legend icon 'image' ？echarts 折线配置项内容和展示

        let pv_image_url = 'image://data:image/svg+xml;base64,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';

    
option = {
      legend: {
          left: 0,
          textStyle:{
            color: '#7C7E92',
            fontSize: 16
          },
          itemWidth: 12,    // 图标的宽高
          itemHeight: 12,
          itemGap: 20,   
          data: [{
            name: '浏览',
            icon: pv_image_url
          }]
       },
      xAxis: {
          type: 'category',
          boundaryGap: false,//这里表示是否补齐空白
          data:['2017-05-01','2017-05-02','2017-05-03']
      },
     yAxis:{
        type : 'value',
        min: 0
    },
    series: [{
          name: '浏览',
          type: 'line',
          smooth: true,
          itemStyle: {
            normal: {
              areaStyle: {
                color: {
                  type: 'linear',
                  x: 0,
                  y: 1,
                  x2: 0,
                  y2: 0,
                  colorStops: [{
                    offset: 0, color: '#fff' // 0% 处的颜色
                  }, {
                    offset: 1, color: '#C9C2E5' // 100% 处的颜色
                  }],
                }
              }
            }
          },
          data:[10,20,30]
        }]
}