code: public static int getSingleBondEquivalentSum(Iterator<IBond> bonds) {
          int sum = 0;
          while (bonds.hasNext()) {
              IBond.Order order = bonds.next().getOrder();
              if (order != null) {
                  sum += order.numeric();
              }
          }
          return sum;
      }
docs: Get the single bond equivalent (SBE) of a list of bonds, given an iterator to the list.
  
  @param bonds An iterator to the list of bonds
  @return The SBE sum