code: public boolean isUnsaturated(IBond bond, IAtomContainer atomContainer) throws CDKException {
          logger.debug("isBondUnsaturated?: ", bond);
          IAtom[] atoms = BondManipulator.getAtomArray(bond);
          boolean isUnsaturated = true;
          for (int i = 0; i < atoms.length && isUnsaturated; i++) {
              isUnsaturated = isUnsaturated && !isSaturated(atoms[i], atomContainer);
          }
          logger.debug("Bond is unsaturated?: ", isUnsaturated);
          return isUnsaturated;
      }
docs: Returns whether a bond is unsaturated. A bond is unsaturated if
  <b>all</b> Atoms in the bond are unsaturated.