final SMARTSAtomInvariants invariants ( final IAtom atom ) { final SMARTSAtomInvariants inv = atom . getProperty ( SMARTSAtomInvariants . KEY ) ; if ( inv == null ) throw new NullPointerException ( "Missing SMARTSAtomInvariants - please compute these values before matching." ) ; return inv ; }
Access the atom invariants for this atom . If the invariants have not been set an exception is thrown .