echarts map地图设置外边框或者阴影

geo: {
              map: \'china\',
              center: [112.194115019531, 23.582111640625],
              zoom: 12,
              aspectScale: 1, //长宽比
              label: {
                normal: {
                  show: true,
                  textStyle: {
                    fontSize: 16,
                    color: \'#ccc\'
                    }
                  },
                emphasis: {
                  show: false,
                  textStyle: {
                    color: \'#ccc\'
                  }
                }
                },
              roam: false,
              itemStyle: {
                normal: {
                  borderColor: "#fff",
                  borderWidth: 5,
                  areaColor: \'#272235\',
                  fontWeightL: 700,
                /*  shadowBlur:20,
                  shadowColor: \'#fff\',*/

                },
                emphasis: {
                  areaColor: {
                    type: \'linear\',
                    x: 0,
                    y: 0,
                    x2: 0,
                    y2: 1,
                    colorStops: [{
                      offset: 0, color: \'#3f15d6\' // 0% 处的颜色
                    }, {
                      offset: 1, color: \'#d243cd\' // 100% 处的颜色
                    }],
                    globalCoord: false // 缺省为 false
                  }
                }
              }
            },


            series: [
              {
                type: \'map\',
                map: \'china\',
                center: [112.194115019531, 23.582111640625],
                zoom: 12,
                geoIndex: 1,
                aspectScale: 1, //长宽比
                showLegendSymbol: false, // 存在legend时显示

                label: {
                  normal: {
                    show: true,
                    textStyle: {
                      fontSize: 16,
                      color: \'#ccc\'
                    }
                  },
                  emphasis: {
                    show: false,
                    textStyle: {
                      color: \'#ccc\'
                    }
                  }
                },
                roam: false,
                itemStyle: {
                  normal: {
                    areaColor: \'#272235\',
                    borderColor: \'#fff\',
                    fontWeightL: 700,
                    borderWidth: 1
                  },
                  emphasis: {
                    areaColor: {
                      type: \'linear\',
                      x: 0,
                      y: 0,
                      x2: 0,
                      y2: 1,
                      colorStops: [{
                        offset: 0, color: \'#3f15d6\' // 0% 处的颜色
                      }, {
                        offset: 1, color: \'#d243cd\' // 100% 处的颜色
                      }],
                      globalCoord: false // 缺省为 false
                    }
                  }
                },
                data: []
              }
              ]