在这个小提琴描述的图表中，x 轴上的日期标签丢失了。谁能告诉我这是为什么？小提琴中的代码如下所示：
$(function () {
var counts = [[635172879695710000, 383], [635172882696280000, 271], [635172885696780000, 274]],
averages = [[635172879695710000, 288774], [635172882696280000, 85592], [635172885696780000, 79455]],
ranges = [[635172879695710000, 12, 2760740], [635172882696280000, 12, 2761263], [635172885696780000, 12, 2761265]];
$('#container').highcharts({
title: {
text: 'Testing!'
},
xAxis: {
type: 'datetime'
},
yAxis: [{
labels: {
format: '{value}B',
style: {
color: '#89A54E'
}
},
title: {
text: 'Size',
style: {
color: '#89A54E'
}
},
min: 0
}, {
labels: {
format: '{value}M',
style: {
color: '#4572A7'
}
},
title: {
text: 'Messages',
style: {
color: '#4572A7'
}
},
min: 0,
opposite: false
}],
tooltip: {
shared: true
},
series: [{
name: 'Line',
type: 'spline',
data: averages,
color: '#89A54E',
zIndex: 1,
marker: {
enabled: false
}
}, {
name: 'Area',
data: ranges,
type: 'areasplinerange',
lineWidth: 0,
linkedTo: ':previous',
color: '#89A54E',
fillOpacity: 0.3,
zIndex: 0
}, {
name: 'Count',
data: counts,
type: 'spline',
zIndex: 2,
color: '#4572A7',
yAxis: 1,
marker: {
enabled: false
}
}]
});
});