怎样每个饼图下面各设置一个标题echarts 饼配置项内容和展示

      option = {
    title: {
        text: 'a',
        left: 'center',
        top: 'bottom'
    },
    tooltip: {
        trigger: 'item',
        formatter: "{a} <br/>{b} : {c} ({d}%)"
    },
    legend: {
        orient: 'horizontal',
        left: 'left',
        data: ['1', '2', '3']
    },
    series: [{
            name: 'zdata[0]',
            type: 'pie',
            center: ['16%', '50%'],
            radius: ['30%', '50%'],
            data: [{
                    name: '1',
                    value: '10'
                },
                {
                    name: '2',
                    value: '20'
                },
                {
                    name: '3',
                    value: '30'
                }
            ]
        },
        {
            name: 'zdata[1]',
            type: 'pie',
            center: ['49%', '50%'],
            radius: ['30%', '50%'],
            data: [{
                    name: '1',
                    value: '10'
                },
                {
                    name: '2',
                    value: '20'
                },
                {
                    name: '3',
                    value: '30'
                }
            ]
        },
        {
            name: 'zdata[2]',
            type: 'pie',
            center: ['82%', '50%'],
            radius: ['30%', '50%'],
            data: [{
                    name: '1',
                    value: '10'
                },
                {
                    name: '2',
                    value: '20'
                },
                {
                    name: '3',
                    value: '30'
                }
            ]
        }
    ]
};