How to use the @swim/view.AnyMemberAnimator function in @swim/view

setCoords(coords: AnyLngLat[], tween?: Tween): void {
    let i = 0;
    for (const n = Math.min(this._coords.length, coords.length); i < n; i += 1) {
      const coord = LngLat.fromAny(coords[i]);
      this._coords[i].setState(coord, tween);
    }
    for (const n = coords.length; i < n; i += 1) {
      const coord = LngLat.fromAny(coords[i]);
      this._coords.push(new AnyMemberAnimator(LngLat, this, coord as LngLat));
      this._points.push(PointR2.origin());
      this.requireUpdate(View.NeedsAnimate | MapView.NeedsProject);
    }
    this._coords.length = coords.length;
  }

appendCoord(coord: AnyLngLat): void {
    coord = LngLat.fromAny(coord);
    this._coords.push(new AnyMemberAnimator(LngLat, this, coord as LngLat));
    this._points.push(PointR2.origin());
    this.requireUpdate(View.NeedsAnimate | MapView.NeedsProject);
  }

insertCoord(index: number, coord: AnyLngLat): void {
    coord = LngLat.fromAny(coord);
    this._coords.splice(index, 0, new AnyMemberAnimator(LngLat, this, coord as LngLat));
    this._points.splice(index, 0, PointR2.origin());
    this.requireUpdate(View.NeedsAnimate | MapView.NeedsProject);
  }