code: function closestOnSegmentData(pointCoordinates, segmentData) {
    const geometry = segmentData.geometry;
  
    if (geometry.getType() === GeometryType.CIRCLE &&
    segmentData.index === CIRCLE_CIRCUMFERENCE_INDEX) {
      return geometry.getClosestPoint(pointCoordinates);
    }
    return closestOnSegment(pointCoordinates, segmentData.segment);
  }
docs: Returns the point closest to a given line segment.
  
  @param {import("../coordinate.js").Coordinate} pointCoordinates The point to which a closest point
  should be found.
  @param {SegmentData} segmentData The object describing the line
  segment which should contain the closest point.
  @return {import("../coordinate.js").Coordinate} The point closest to the specified line segment.