def from_track_dict(cls, d, frame_size):
        """Creates a :class:`CVATTrack` from a ``<track>`` tag of a CVAT video
        annotation XML file.

        Args:
            d: a dict representation of an ``<track>`` tag
            frame_size: the ``(width, height)`` of the video frames

        Returns:
            a :class:`CVATTrack`
        """
        id = d["@id"]
        label = d["@label"]

        width, height = frame_size

        boxes = {}
        for bd in _ensure_list(d.get("box", [])):
            box = CVATVideoBox.from_box_dict(label, bd)
            boxes[box.frame] = box

        polygons = {}
        for pd in _ensure_list(d.get("polygon", [])):
            polygon = CVATVideoPolygon.from_polygon_dict(label, pd)
            polygons[polygon.frame] = polygon

        polylines = {}
        for pd in _ensure_list(d.get("polyline", [])):
            polyline = CVATVideoPolyline.from_polyline_dict(label, pd)
            polylines[polyline.frame] = polyline

        points = {}
        for pd in _ensure_list(d.get("points", [])):
            point = CVATVideoPoints.from_points_dict(label, pd)
            points[point.frame] = point

        return cls(
            id,
            label,
            width,
            height,
            boxes=boxes,
            polygons=polygons,
            polylines=polylines,
            points=points,
        )
Creates a :class:`CVATTrack` from a ``<track>`` tag of a CVAT video
        annotation XML file.

        Args:
            d: a dict representation of an ``<track>`` tag
            frame_size: the ``(width, height)`` of the video frames

        Returns:
            a :class:`CVATTrack`
        
fiftyone/utils/cvat.py