百度地图API 怎么显示多条公交线路

    var busline = new BMap.BusLineSearch(map,{
        renderOptions:{map:map,panel:"r-result"},
        onGetBusListComplete: function(result){
            if(result) {
                var fstLine = result.getBusListItem(0);//获取第一个公交列表显示到map上
                busline.getBusLine(fstLine);
            }
        }
    });

    var busline1 = new BMap.BusLineSearch(map,{
        renderOptions:{map:map,panel:"r-result"},
        onGetBusListComplete: function(result){
            if(result) {
                var fstLine = result.getBusListItem(0);//获取第一个公交列表显示到map上
                busline1.getBusLine(fstLine);
            }
        }
    });
    function busSearch(){
        var busName = 331;
        busline.getBusList(busName);
        busline1.getBusList(659);
    }
    setTimeout(function(){
        busSearch();
    },1500);