How do I create a chart with rounded corners?

I have created a Chartist line chart and I want to make the corners of the chart rounded like in the image bellow:

Where do I need to set up the attribute or is even possible to make it looking like I want ?

new Chartist.Line('#dashboardChartStats1', {
    labels: [1, 2, 3, 4, 5, 6, 7],
    series: [
        [5, 6, 7, 4, 7, 6, 5]
    ]
}, {
    low: 0,
    high: 10,
    showArea: true,
    fullWidth: true,
    axisX: {
        offset: 0,
        showLabel: false
    },
    axisY: {
        offset: 0,
        showGrid: false,
        showLabel: false
    },
    lineSmooth: Chartist.Interpolation.cardinal({
        tension: 1,
        fillHoles: false
    })
});

It is doable with border-radius;

svg {
  border-radius: 50%;
}

though it does looks a bit ugly, but you can fiddle with it; fiddle here

There is no way to do this via the controls of the chart library. Maybe some css magic can make it better, but I am all out of mana. 🧙

Also embedded below;

new Chartist.Line('.container', {
    labels: [1, 2, 3, 4, 5, 6, 7],
    series: [
        [5, 6, 7, 4, 7, 6, 5]
    ]
}, {
    low: 0,
    high: 10,
    showArea: true,
    fullWidth: true,
    axisX: {
        offset: 0,
        showLabel: false
    },
    axisY: {
        offset: 0,
        showGrid: false,
        showLabel: false
    },
    lineSmooth: Chartist.Interpolation.cardinal({
        tension: 1,
        fillHoles: false
    })
});

.container {
  width: 300px;
  height: 300px;
}

svg {
    border-radius: 50%;
}

<script src="https://rawgit.com/gionkunz/chartist-js/master/dist/chartist.min.js"></script>
<link href="https://rawgit.com/gionkunz/chartist-js/master/dist/chartist.min.css" rel="stylesheet"/>

<div class="container"></div>