hide values in stacked area chart to avoid zero padding to clean up hovertool

When I hover over a stacked line chart, it shows zeroes for all lines not in range. Is there a way to hide these values rather than adding noise to the hover tool?

Plotly.newPlot('test', [{
    line: { shape : 'vh' },
    stackgroup: '1',
    x: [1, 2],
    y: [1, 1],
}, {
    line: { shape : 'vh' },
    stackgroup: '1',
    x: [3, 4],
    y: [2, 2],
}, {
    line: { shape : 'vh' },
    stackgroup: '1',
    x: [3, 4, 5, 6],
    y: [3, 3, 3, 3],
}], {
    hovermode: 'x unified',
    width: '100%',
});

As a jsfiddle and image:

(Cross-post from StackOverflow, which also provides an example use case where this matters)

从使用 Plotly.newPlot 和 hovermode "x unified" 的 JavaScript 复现开始；确认带有超出范围 x 值的堆叠面积轨迹在 hover 工具中的显示方式。将其行为与链接的 jsfiddle 进行比较，并将所描述的零值显示作为验收案例。完成的标准是隐藏不相关的零值，同时不遮挡其余的 hover 值。