echarts饼图鼠标移入时，悬停部分不放大突出 属性 ？

option = {
    tooltip: {
        trigger: 'item'
    },
    legend: {
        orient: 'vertical',
        left: 'left',
    },
    series: [
        {
            name: '访问来源',
            type: 'pie',
            radius: ['35%', '30%'],
            hoverAnimation:false,
            data: [
                {value: 1048, name: '搜索引擎'},
                {value: 735, name: '直接访问'},
                {value: 580, name: '邮件营销'},
                {value: 484, name: '联盟广告'},
                {value: 300, name: '视频广告'}
            ]
            
        }
    ]
};