constructor(firstRing, secondRing) {
    this.id = null;
    this.firstRingId = firstRing.id;
    this.secondRingId = secondRing.id;
    this.vertices = new Set();

    for (var m = 0; m < firstRing.members.length; m++) {
      let c = firstRing.members[m];

      for (let n = 0; n < secondRing.members.length; n++) {
        let d = secondRing.members[n];

        if (c === d) {
          this.addVertex(c);
        }
      }
    }
  }
The constructor for the class RingConnection.

@param {Ring} firstRing A ring.
@param {Ring} secondRing A ring.