有没有人用过百度的Echarts？刚开始接触，下面这段代码怎么理解啊，新手求指教：

myChart.showLoading();

$.get('data/asset/data/les-miserables.gexf', function (xml) {

myChart.hideLoading();

var graph = echarts.dataTool.gexf.parse(xml);

var categories = [];

for (var i = 0; i < 9; i++) {

categories[i] = {

name: '类目' + i

};

}

graph.nodes.forEach(function (node) {

node.itemStyle = null;

node.value = node.symbolSize;

node.label = {

normal: {

show: node.symbolSize > 30

}

};

node.category = node.attributes.modularity_class;

});