code: public static double getBondLengthAverage(IReaction reaction) {
          double bondlenghtsum = 0.0;
          int containercount = 0;
          List<IAtomContainer> containers = ReactionManipulator.getAllAtomContainers(reaction);
          for (IAtomContainer container : containers) {
              containercount++;
              bondlenghtsum += getBondLengthAverage(container);
          }
          return bondlenghtsum / containercount;
      }
docs: /*
  Returns the average 2D bond length values of all products and reactants
  of the given reaction. The method uses {@link
  #getBondLengthAverage(IAtomContainer)} internally.
  @param reaction The IReaction for which the average 2D bond length is
  calculated
  @return the average 2D bond length
  @see #getBondLengthAverage(IAtomContainer)