amcharts如何隐藏图例

Question

    "graphs": [{
        "valueAxis": "v1",
        "lineColor": "blue",
        "bullet": "round",
        "bulletBorderThickness": 1,
        "hideBulletsCount": 30,
     
        "valueField": "visits",
		"fillAlphas": 0
    }, {
        "valueAxis": "v2",
        "lineColor": "pink",
        "bullet": "square",
        "bulletBorderThickness": 1,
        "hideBulletsCount": 30,
        "title": "yellow line",
        "valueField": "hits",
		"fillAlphas": 0
    }],

如图,删除title属性,然而还会留下一个图例,removeLegend()会删掉所有图例,求删掉底部蓝色图例.