code: private Set<IChemObject> getAromatics(IAtomContainer mol) {
          Set<IChemObject> oldArom = new HashSet<>();
          for (IAtom atom : mol.atoms())
              if (atom.getFlag(CDKConstants.ISAROMATIC))
                  oldArom.add(atom);
          for (IBond bond : mol.bonds())
              if (bond.getFlag(CDKConstants.ISAROMATIC))
                  oldArom.add(bond);
          return oldArom;
      }
docs: Helper method to find all existing aromatic chem objects.
  
  @param mol molecule
  @return chem objects