PathGraphics not working in real-time or runtime generated - entity

Question

Have simple app using Cesium. I have basic entity with ellipse graphics, moving around, and I need to display its path, using PathGraphics, but it doesn't seem to work for me.
Here's code sample.
const position = new SampledPositionProperty();
const start = [16.096912, 40.4100289];
const startTime = JulianDate.now();
position.addSample(startTime, Cartesian3.fromDegrees(...start));
const diff = 0.0002;
const [x, y] = start;
for (let i = 0; i < 10; i += 1) {
const d = JulianDate.addSeconds(startTime, i + 1, new JulianDate());
const newPos = [x + diff * (i + 1), y + diff * (i + 1)];
position.addSample(d, Cartesian3.fromDegrees(...newPos));
}
app.entities.add({
ellipse: {
semiMinorAxis: 10,
semiMajorAxis: 10,
material: Color.RED,
},
path: {
resolution: 1,
width: 5,
material: Color.YELLOW,
},
position,
});
But when I launch it all I see is moving ellipse, but no path is drawn. Everywhere I searched they say you just have to have position as SampledProperty and it will work, but it doesn't seem to work for me.
In this case, as you can see, I generate data beforehand, but I also tried adding it in runtime - same result. The only working examples i was able to find where using czml - but it doesn't fit my needs - it will be real-time app.

Answer 1

I found the solution by digging through Cesium Sandcastle - you have to set availability property to entity with time range you want path to be shown. Would be cool if it was covered in documentation at least in some way.