function readBoundingBox(node, objectStack) {
  const coordinates = pushParseAndPop(
    [],
    WGS84_BBOX_READERS,
    node,
    objectStack,
  );
  if (coordinates.length != 2) {
    return undefined;
  }
  return boundingExtent(coordinates);
}
@param {Element} node Node.
@param {Array<*>} objectStack Object stack.
@return {Object|undefined} BBox object.