doTypeChecks(a, b) {
    const checkArrayOne = a.getCheck();
    const checkArrayTwo = b.getCheck();

    if (!checkArrayOne || !checkArrayTwo) {
      // Null arrays can only connect to other null arrays.
      return checkArrayOne == checkArrayTwo;
    }

    // Find any intersection in the check lists.
    for (let i = 0; i < checkArrayOne.length; i++) {
      if (checkArrayTwo.indexOf(checkArrayOne[i]) != -1) {
        return true;
      }
    }
    // No intersection.
    return false;
  }
Type check arrays must either intersect or both be null.
@override