code: private static <T extends Storable> int
          commonOrderingCount(OrderingList<T> orderingA, OrderingList<T> orderingB)
      {
          int commonCount = Math.min(orderingA.size(), orderingB.size());
  
          for (int i=0; i<commonCount; i++) {
              if (!orderingA.get(i).equals(orderingB.get(i))) {
                  return i;
              }
          }
  
          return commonCount;
      }
docs: Returns the count of exactly matching properties from the two
  orderings. The match must be consecutive and start at the first
  property.