关于桑基图对齐问题echarts sankey配置项内容和展示

请看最右侧下方的 “Working hours” 节点，为什么该 三级节点(没有四级子节点) 就不能对齐到其他 三级节点(有四级子节点) 位置呢？ 原Demo网址：http://echarts.baidu.com/demo.html#sankey-product 改动处：将 data中的 “Working hours” 子节点全部删除

      
    var data = {"nodes": [
      {"name": "Total"},
      {"name": "Environment"},
      {"name": "Land use"},
      {"name": "Cocoa butter (Organic)"},
      {"name": "Cocoa mass (Organic)"},
      {"name": "Hazelnuts (Organic)"},
      {"name": "Cane sugar (Organic)"},
      {"name": "Vegetables (Organic)"},
      {"name": "Climate change"},
      {"name": "Harmful substances"},
      {"name": "Water use"},
      {"name": "Resource depletion"},
      {"name": "Refrigeration"},
      {"name": "Packaging"},
      {"name": "Human rights"},
      {"name": "Child labour"},
      {"name": "Coconut oil (Organic)"},
      {"name": "Forced labour"},
      {"name": "Health safety"},
      {"name": "Access to water"},
      {"name": "Freedom of association"},
      {"name": "Access to land"},
      {"name": "Sufficient wage"},
      {"name": "Equal rights migrants"},
      {"name": "Discrimination"},
      {"name": "Working hours"}
   ],
   "links": [
      {"source": "Total", "target": "Environment", "value": 0.342284047256003},
      {"source": "Environment", "target": "Land use", "value": 0.32322870366987},
      {"source": "Land use", "target": "Cocoa butter (Organic)", "value": 0.177682517071359},
      {"source": "Land use", "target": "Cocoa mass (Organic)", "value": 0.137241325342711},
      {"source": "Land use", "target": "Hazelnuts (Organic)", "value": 0.00433076373512774},
      {"source": "Land use", "target": "Cane sugar (Organic)", "value": 0.00296956039863467},
      {"source": "Land use", "target": "Vegetables (Organic)", "value": 0.00100453712203756},
      {"source": "Environment", "target": "Climate change", "value": 0.0112886157414413},
      {"source": "Climate change", "target": "Cocoa butter (Organic)", "value": 0.00676852971933996},
      {"source": "Climate change", "target": "Cocoa mass (Organic)", "value": 0.00394686874786743},
      {"source": "Climate change", "target": "Cane sugar (Organic)", "value": 0.000315972058711838},
      {"source": "Climate change", "target": "Hazelnuts (Organic)", "value": 0.000218969462265292},
      {"source": "Climate change", "target": "Vegetables (Organic)", "value": 3.82757532567656e-05},
      {"source": "Environment", "target": "Harmful substances", "value": 0.00604275542495656},
      {"source": "Harmful substances", "target": "Cocoa mass (Organic)", "value": 0.0055125989240741},
      {"source": "Harmful substances", "target": "Cocoa butter (Organic)", "value": 0.000330017607892127},
      {"source": "Harmful substances", "target": "Cane sugar (Organic)", "value": 0.000200138892990337},
      {"source": "Harmful substances", "target": "Hazelnuts (Organic)", "value": 0},
      {"source": "Harmful substances", "target": "Vegetables (Organic)", "value": 0},
      {"source": "Environment", "target": "Water use", "value": 0.00148345269044703},
      {"source": "Water use", "target": "Cocoa butter (Organic)", "value": 0.00135309891304186},
      {"source": "Water use", "target": "Cocoa mass (Organic)", "value": 0.000105714137908639},
      {"source": "Water use", "target": "Hazelnuts (Organic)", "value": 1.33452642581887e-05},
      {"source": "Water use", "target": "Cane sugar (Organic)", "value": 8.78074837009238e-06},
      {"source": "Water use", "target": "Vegetables (Organic)", "value": 2.5136268682477e-06},
      {"source": "Environment", "target": "Resource depletion", "value": 0.000240519729288764},
      {"source": "Resource depletion", "target": "Cane sugar (Organic)", "value": 0.000226237279345084},
      {"source": "Resource depletion", "target": "Vegetables (Organic)", "value": 1.42824499436793e-05},
      {"source": "Resource depletion", "target": "Hazelnuts (Organic)", "value": 0},
      {"source": "Resource depletion", "target": "Cocoa mass (Organic)", "value": 0},
      {"source": "Resource depletion", "target": "Cocoa butter (Organic)", "value": 0},
      {"source": "Environment", "target": "Refrigeration", "value": 0},
      {"source": "Environment", "target": "Packaging", "value": 0},
      {"source": "Total", "target": "Human rights", "value": 0.307574096993239},
      {"source": "Human rights", "target": "Child labour", "value": 0.0410641202645833},
      {"source": "Child labour", "target": "Hazelnuts (Organic)", "value": 0.0105339381639722},
      {"source": "Child labour", "target": "Cocoa mass (Organic)", "value": 0.0105},
      {"source": "Child labour", "target": "Cocoa butter (Organic)", "value": 0.0087294420777},
      {"source": "Child labour", "target": "Coconut oil (Organic)", "value": 0.00474399974233333},
      {"source": "Child labour", "target": "Cane sugar (Organic)", "value": 0.00388226450884445},
      {"source": "Child labour", "target": "Vegetables (Organic)", "value": 0.00267447577173333},
      {"source": "Human rights", "target": "Forced labour", "value": 0.0365458590642445},
      {"source": "Forced labour", "target": "Hazelnuts (Organic)", "value": 0.0114913076376389},
      {"source": "Forced labour", "target": "Cocoa butter (Organic)", "value": 0.0081134807347},
      {"source": "Forced labour", "target": "Cocoa mass (Organic)", "value": 0.00765230236575},
      {"source": "Forced labour", "target": "Cane sugar (Organic)", "value": 0.004},
      {"source": "Forced labour", "target": "Vegetables (Organic)", "value": 0.00296668823626667},
      {"source": "Forced labour", "target": "Coconut oil (Organic)", "value": 0.00232208008988889},
      {"source": "Human rights", "target": "Health safety", "value": 0.0345435327843611},
      {"source": "Health safety", "target": "Hazelnuts (Organic)", "value": 0.0121419536385},
      {"source": "Health safety", "target": "Cocoa mass (Organic)", "value": 0.00766772850678333},
      {"source": "Health safety", "target": "Cocoa butter (Organic)", "value": 0.0056245892061},
      {"source": "Health safety", "target": "Coconut oil (Organic)", "value": 0.00361616847688889},
      {"source": "Health safety", "target": "Cane sugar (Organic)", "value": 0.00277374682533333},
      {"source": "Health safety", "target": "Vegetables (Organic)", "value": 0.00271934613075556},
      {"source": "Human rights", "target": "Access to water", "value": 0.0340206659360667},
      {"source": "Access to water", "target": "Cocoa mass (Organic)", "value": 0.0105},
      {"source": "Access to water", "target": "Cocoa butter (Organic)", "value": 0.0089274160792},
      {"source": "Access to water", "target": "Hazelnuts (Organic)", "value": 0.0054148022845},
      {"source": "Access to water", "target": "Cane sugar (Organic)", "value": 0.00333938149786667},
      {"source": "Access to water", "target": "Vegetables (Organic)", "value": 0.00314663377488889},
      {"source": "Access to water", "target": "Coconut oil (Organic)", "value": 0.00269243229961111},
      {"source": "Human rights", "target": "Freedom of association", "value": 0.0320571523941667},
      {"source": "Freedom of association", "target": "Hazelnuts (Organic)", "value": 0.0132312483463611},
      {"source": "Freedom of association", "target": "Cocoa butter (Organic)", "value": 0.0077695200707},
      {"source": "Freedom of association", "target": "Cocoa mass (Organic)", "value": 0.00510606573995},
      {"source": "Freedom of association", "target": "Vegetables (Organic)", "value": 0.00354321156324444},
      {"source": "Freedom of association", "target": "Cane sugar (Organic)", "value": 0.00240710667391111},
      {"source": "Freedom of association", "target": "Coconut oil (Organic)", "value": 0},
      {"source": "Human rights", "target": "Access to land", "value": 0.0315022209894056},
      {"source": "Access to land", "target": "Hazelnuts (Organic)", "value": 0.00964970063322223},
      {"source": "Access to land", "target": "Cocoa mass (Organic)", "value": 0.00938530207965},
      {"source": "Access to land", "target": "Cocoa butter (Organic)", "value": 0.0060110791848},
      {"source": "Access to land", "target": "Cane sugar (Organic)", "value": 0.00380818314608889},
      {"source": "Access to land", "target": "Vegetables (Organic)", "value": 0.00264795594564445},
      {"source": "Access to land", "target": "Coconut oil (Organic)", "value": 0},
      {"source": "Human rights", "target": "Sufficient wage", "value": 0.0287776757227333},
      {"source": "Sufficient wage", "target": "Cocoa mass (Organic)", "value": 0.00883512456493333},
      {"source": "Sufficient wage", "target": "Cocoa butter (Organic)", "value": 0.0078343367268},
      {"source": "Sufficient wage", "target": "Coconut oil (Organic)", "value": 0.00347879026511111},
      {"source": "Sufficient wage", "target": "Hazelnuts (Organic)", "value": 0.00316254211388889},
      {"source": "Sufficient wage", "target": "Vegetables (Organic)", "value": 0.00281013722808889},
      {"source": "Sufficient wage", "target": "Cane sugar (Organic)", "value": 0.00265674482391111},
      {"source": "Human rights", "target": "Equal rights migrants", "value" : 0.0271146645119444},
      {"source": "Equal rights migrants", "target": "Cocoa butter (Organic)", "value": 0.0071042315061},
      {"source": "Equal rights migrants", "target": "Cocoa mass (Organic)", "value": 0.00636673210005},
      {"source": "Equal rights migrants", "target": "Hazelnuts (Organic)", "value": 0.00601459775836111},
      {"source": "Equal rights migrants", "target": "Coconut oil (Organic)", "value": 0.00429185583138889},
      {"source": "Equal rights migrants", "target": "Cane sugar (Organic)", "value": 0.00182647471915556},
      {"source": "Equal rights migrants", "target": "Vegetables (Organic)", "value": 0.00151077259688889},
      {"source": "Human rights", "target": "Discrimination", "value": 0.0211217763359833},
      {"source": "Discrimination", "target": "Cocoa mass (Organic)", "value": 0.00609671700306667},
      {"source": "Discrimination", "target": "Cocoa butter (Organic)", "value": 0.0047738806325},
      {"source": "Discrimination", "target": "Coconut oil (Organic)", "value": 0.00368119084494444},
      {"source": "Discrimination", "target": "Vegetables (Organic)", "value": 0.00286009813604444},
      {"source": "Discrimination", "target": "Cane sugar (Organic)", "value": 0.00283706180951111},
      {"source": "Discrimination", "target": "Hazelnuts (Organic)", "value": 0.000872827909916666},
      {"source": "Human rights", "target": "Working hours", "value": 0.02082642898975}
   ]}
   
   option = {
        title: {
            text: 'Sankey Diagram'
        },
        tooltip: {
            trigger: 'item',
            triggerOn: 'mousemove'

        },
        series: [
            {
                type: 'sankey',
                layout:'none',
                data: data.nodes,
                links: data.links,
                itemStyle: {
                    normal: {
                        borderWidth: 1,
                        borderColor: '#aaa'
                    }
                },
                lineStyle: {
                    normal: {
                        curveness: 0.5
                    }
                }
            }
        ]
    }