code: private List<Integer[]> getAtomNoPairsForRingGroup(IAtomContainer molecule, List<Integer> bondsToCheck) {
          List<Integer[]> aptc = new ArrayList<Integer[]>();
          for (Integer i : bondsToCheck) {
              Integer[] aps = new Integer[2];
              aps[0] = molecule.indexOf(molecule.getBond(i).getBegin());
              aps[1] = molecule.indexOf(molecule.getBond(i).getEnd());
              aptc.add(aps);
          }
          return aptc;
      }
docs: Gets List of atom number pairs for each bond in a list of bonds for the molecule.
  
  @param {@link IAtomContainer} molecule
  @param bondsToCheck
  @return List of atom pairs