树图roam属性echarts tree配置项内容和展示

加入roam属性（4.2测试版本）后，点击一级父节点树图移位严重

      option = {
    tooltip: {
        trigger: 'item',
        triggerOn: 'mousemove'
    },
    series: [{
        type: 'tree',

        data: [{
            name: '1号',
            children: [{
                    name: '2号'
                },
                {
                    name: '3号'
                },
                {
                    name: '4号',
                    children: [{
                        name: '6号'
                    }, {
                        name: '7号'
                    }, {
                        name: '8号'
                    }, ]
                },
                {
                    name: '5号'
                },
            ]
        }],
        roam: true,
        top: '1%',
        left: '7%',
        bottom: '1%',
        right: '20%',

        symbolSize: 7,

        label: {
            normal: {
                position: 'left',
                verticalAlign: 'middle',
                align: 'right',
                fontSize: 9
            }
        },

        leaves: {
            label: {
                normal: {
                    position: 'right',
                    verticalAlign: 'middle',
                    align: 'left'
                }
            }
        },

        expandAndCollapse: true,
        animationDuration: 550,
        animationDurationUpdate: 750
    }]
}