appendLinearRing(linearRing) {
    if (!this.flatCoordinates) {
      this.flatCoordinates = linearRing.getFlatCoordinates().slice();
    } else {
      extend(this.flatCoordinates, linearRing.getFlatCoordinates());
    }
    this.ends_.push(this.flatCoordinates.length);
    this.changed();
  }
Append the passed linear ring to this polygon.
@param {LinearRing} linearRing Linear ring.
@api