Why not option loop not work with polyline entity?

CesiumJS
1

This is the demo of cesiumjs, I add option loop true, but it not work.

var redLine = viewer.entities.add({
    name : 'Red line on terrain',
    polyline : {
        positions : Cesium.Cartesian3.fromDegreesArray([-75, 35,
                                                        -125, 35,
                                                        -100, 35]),
        width : 5,
        material : Cesium.Color.RED,
        clampToGround : true,
        loop: true
    }
});

2

The PolylineGraphics object does not take a loop option. See the documentation here:

https://cesiumjs.org/Cesium/Build/Documentation/PolylineGraphics.html?classFilter=Polylin

Although there is an issue open for it to add support:

https://github.com/AnalyticalGraphicsInc/cesium/issues/7202

Feel free to add your thoughts or chime in there.