Highcharts Gantt图表：在Y轴配置上不支持类别声明的Y轴上的父子功能

如何解决Highcharts Gantt图表：在Y轴配置上不支持类别声明的Y轴上的父子功能

我正在使用Highcharts Gantt图表绘制甘特图。我在数据中使用父关键字进行分组。当我为YAxis配置提供类别时，它不支持父子分组。

我使用的参考：https://jsfiddle.net/gh/get/library/pure/highcharts/highcharts/tree/master/samples/gantt/demo/subtasks

预期具有相同的输出，但具有YAxis类别（要实现拖放功能，为此，我们需要Y轴类别）。

示例代码：

var today = new Date(),day = 1000 * 60 * 60 * 24;

// Set to 00:00:00:000 today
today.setUTCHours(0);
today.setUTCMinutes(0);
today.setUTCSeconds(0);
today.setUTCMilliseconds(0);


// THE CHART
Highcharts.ganttChart('container',{
    title: {
        text: 'Highcharts Gantt With Subtasks'
    },xAxis: {
        min: today.getTime() - (2 * day),max: today.getTime() + (32 * day)
    },yAxis: {
        min: 0,max: 3,categories: ['Planning','Requirements','Design']
    },series: [{
        name: 'Project 1',data: [{
            name: 'Planning',id: 'planning',start: today.getTime(),end: today.getTime() + (20 * day),y: 0
        },{
            name: 'Requirements',id: 'requirements',parent: 'planning',end: today.getTime() + (5 * day),y: 1
        },{
            name: 'Design',id: 'design',dependency: 'requirements',start: today.getTime() + (3 * day),y: 2
        },{
            name: 'Layout',id: 'layout',parent: 'design',end: today.getTime() + (10 * day),y: 3
        },{
            name: 'Graphics',dependency: 'layout',start: today.getTime() + (10 * day),y: 4
        },{
            name: 'Develop',id: 'develop',start: today.getTime() + (5 * day),end: today.getTime() + (30 * day),y: 5
        },{
            name: 'Create unit tests',id: 'unit_tests',parent: 'develop',end: today.getTime() + (8 * day),y: 6
        },{
            name: 'Implement',id: 'implement',dependency: 'unit_tests',start: today.getTime() + (8 * day),y: 7
        }]
    }]
});

#container {
    max-width: 800px;
    margin: 1em auto;
}

<script src="https://code.highcharts.com/gantt/highcharts-gantt.js"></script>


<div id="container"></div>