在线定制下载的echart脚本不支持渐变色方法？echarts 柱状配置项内容和展示

在线定制下载的echart脚本不支持渐变色方法？ 浏览器报错 Cannot read property 'LinearGradient' of undefined； 请问 LinearGradient方法应该打包那个组件？

      option = {
    color: ['#4790a0'],
    title: {
        text: '类型分布图',
        x: 'center',
        top: 10,
    },
    tooltip: {
        trigger: 'axis',
    },
    grid: {
        left: '3%',
        right: '4%',
        bottom: '3%',
        containLabel: true
    },
    xAxis: [{
        type: 'category',
        data: ['类型1', '类型2', '类型3', '类型4'],
        axisTick: {
            // alignWithLabel: true
        }
    }],
    yAxis: [{
        type: 'value',
        minInterval: 1
    }],
    series: [{
        name: '数量',
        type: 'bar',
        barWidth: '30%',
        animationDelay: function(idx) {
            return idx * 100;
        },
        data: [16,23,8,19],
        itemStyle: {
            normal: {
                color: new echarts.graphic.LinearGradient(
                    0, 0, 0, 1, [{
                        offset: 0,
                        color: '#60c4da'
                    }, {
                        offset: 0.5,
                        color: '#4790a0'
                    }, {
                        offset: 1,
                        color: '#336671'
                    }]
                ),
                barBorderRadius: [3, 3, 0, 0]
            },
            emphasis: {
                color: '#4790a0'
            }
        },
    }]
};