readFlatLinearRing(node, objectStack) {
    const ring = pushParseAndPop(
      null,
      this.GEOMETRY_FLAT_COORDINATES_PARSERS,
      node,
      objectStack,
      this,
    );
    if (ring) {
      return ring;
    }
    return undefined;
  }
@param {Element} node Node.
@param {Array<*>} objectStack Object stack.
@return {Array<number>|undefined} LinearRing flat coordinates.