Graph -双向箭头如何在线的两边出现文字echarts graph配置项内容和展示

Graph -双向箭头如何在线的两边出现文字

              option = {
            title: {
                text: 'Graph 简单示例'
            },
            // tooltip: {},
            series: [{
                type: 'graph',
                layout: 'force',
                symbolSize: 60,
                roam: true,
                edgeSymbol: ['circle', 'arrow'],
                edgeSymbolSize: [4, 10],
                focusNodeAdjacency: true,
                force: {
                    repulsion: 1200,
                    edgeLength: 300,
                    gravity: 0.4,

                },
                symbol: "circle",
                itemStyle: {
                    normal: {
                        color: '#0084ff'
                    }
                },
                lineStyle: {
                    normal: {
                        width: 2

                    }
                },
                edgeLabel: {
                    normal: {
                        show: true,
                        formatter: function(x) {
                            return x.data.name;
                        }
                    }
                },
                label: {

                    normal: {
                        show: true,
                        textStyle: {
                            fontSize: 10
                        }
                    }
                },
                data: [{
                    "name": "公司1"
                }, {
                    "name": "公司2"
                }],
                // links: [],
                links: [{
                    "source": "公司1",
                    "target": "公司2",
                    "name": "控股20",
                    "label": {
                        color: 'red',
                        verticalAlign: 'bottom',
                        padding: [10, 10, 10, 10],
                        padding: 0,
                        "show": true
                    }
                }, {
                    "source": "公司2",
                    "target": "公司1",
                    "name": "控股30",
                    "label": {
                        color: 'blue',
                        verticalAlign: 'top',
                        padding: [10, 10, 10, 10],
                        "show": true
                    }
                }]
            }]
        };