function readCoordinates(node, objectStack) {
  const coordinates = readString(node).split(/\s+/);
  if (!coordinates || coordinates.length != 2) {
    return undefined;
  }
  const x = +coordinates[0];
  const y = +coordinates[1];
  if (isNaN(x) || isNaN(y)) {
    return undefined;
  }
  return [x, y];
}
@param {Node} node Node.
@param {Array<*>} objectStack Object stack.
@return {Object|undefined} Coordinates object.