code: public static int convertBondOrder(IBond bond) {
          int value = 0;
          switch (bond.getOrder()) {
              case QUADRUPLE:
                  value = 4;
                  break;
              case TRIPLE:
                  value = 3;
                  break;
              case DOUBLE:
                  value = 2;
                  break;
              case SINGLE:
                  value = 1;
                  break;
              default:
                  value = 0;
          }
          return value;
      }
docs: Get bond order value as {@code int} value.
  
  @param  bond The {@link IBond} for which the order is returned.
  @return      1 for a single bond, 2 for a double bond, 3 for a triple bond, 4 for a quadruple bond,
  and 0 for any other bond type.