code: private double getAtomBondordersum(IAtom atom, IAtomContainer mol) throws CDKException {
          double sum = 0;
  
          for (IBond bond : mol.bonds())
              if (bond.contains(atom)) sum += BondManipulator.destroyBondOrder(bond.getOrder());
  
          return sum;
      }
docs: This method is used if, by some reason, the bond order sum is not set
  for an atom.
  
  @param atom The atom in question
  @param mol The molecule that the atom belongs to
  @return The bond order sum
  @throws CDKException