clone() {
    let clone = new Ring(this.members);
    clone.id = this.id;
    clone.insiders = ArrayHelper.clone(this.insiders);
    clone.neighbours = ArrayHelper.clone(this.neighbours);
    clone.positioned = this.positioned;
    clone.center = this.center.clone();
    clone.rings = ArrayHelper.clone(this.rings);
    clone.isBridged = this.isBridged;
    clone.isPartOfBridged = this.isPartOfBridged;
    clone.isSpiro = this.isSpiro;
    clone.isFused = this.isFused;
    clone.centralAngle = this.centralAngle;
    clone.canFlip = this.canFlip;
    return clone;
  }
Clones this ring and returns the clone.

@returns {Ring} A clone of this ring.