class AtomSignature extends AbstractVertexSignature {

    @Override
    /** {@inheritDoc} */
    protected int getIntLabel(int vertexIndex) {
        IAtom atom = molecule.getAtom(vertexIndex);
        return atom.getMassNumber();
    }

    public  AtomSignature(int atomIndex, IAtomContainer molecule);
    public  AtomSignature(IAtom atom, IAtomContainer molecule);
    public  AtomSignature(int atomIndex, int height, IAtomContainer molecule);
    public  AtomSignature(IAtom atom, int height, IAtomContainer molecule);
    public  AtomSignature(int atomIndex, int height, InvariantType invariantType, IAtomContainer molecule);
    public  AtomSignature(IAtom atom, int height, InvariantType invariantType, IAtomContainer molecule);

}