自定义系列问题"This coordSys does not support custom series"echarts effectScatter配置项内容和展示

在option中添加custom，浏览器调试提示：Uncaught Error: This coordSys does not support custom series. 在网上没搜到相关答案，比较疑惑，是指bmap不支持自定义吗？明明看gallery中有作者已实现了custom，而且用的bmap. 比较疑惑，请大神解答。

      option = {

        bmap: {
            center: [104.114129, 37.550339],
            zoom: 5,
            roam: true
        },

        title: [{
            text: 'test',
            subtext: '',
            left: 'center',
            textStyle: {color: '#fff'}
            }],

        xAxis: {
        },
        yAxis: {

        },

        series: [
            //地图点的动画效果
            {
                //  name: 'Top 5',
                type: 'effectScatter',
                coordinateSystem: 'bmap',
                data: convertData(mapData[0].sort(function (a, b) {
                    return b.value - a.value;
                }).slice(0, 20)),
                symbolSize: function (val) {
                    return val[2] / 10;
                },
                showEffectOn: 'render',
                rippleEffect: {
                    brushType: 'stroke'
                },
                hoverAnimation: true,
                label: {
                    normal: {
                        formatter: '{b}',
                        position: 'right',
                        show: true
                    }
                },
                itemStyle: {
                    normal: {
                        color: colors[colorIndex][0],
                        shadowBlur: 10,
                        shadowColor: colors[colorIndex][0]
                    }
                },
                zlevel: 1
            },

            //区域
            {
                type: 'custom',
                coordinateSystem: 'bmap',
                renderItem: renderItem,
                itemStyle: {
                    opacity: 0.5
                },
                animation: false,
                silent: true,
                data: [0],
                z: -10
            }
        ]
    }