#vulnerable code 
                                private void prepare() {
        AbyssExtractorOpposites opposites = new AbyssExtractorOpposites();

        for (int i = 0; i < tokenizedSource.size(); i++) {
            TokenRepresentation representation = tokenizedSource.get(i);
            Token token = representation.getToken();

            boolean levelUp = opposites.report(token);
            int nestingLevel = levelUp ? opposites.getNestingLevel() - 1 : opposites.getNestingLevel();

            AbyssTokenRepresentation abyssRepresentation = new AbyssTokenRepresentation(representation, nestingLevel);
            abyssRepresentations[i] = abyssRepresentation;
        }
    } 
                            #location 6 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                private void prepare() {
        AbyssExtractorOpposites opposites = new AbyssExtractorOpposites();

        for (int i = 0; i < tokenizedSource.size(); i++) {
            TokenRepresentation representation = tokenizedSource.get(i);

            if (representation == null) {
                throw new PandaRuntimeException("Representation is null");
            }

            Token token = representation.getToken();

            boolean levelUp = opposites.report(token);
            int nestingLevel = levelUp ? opposites.getNestingLevel() - 1 : opposites.getNestingLevel();

            AbyssTokenRepresentation abyssRepresentation = new AbyssTokenRepresentation(representation, nestingLevel);
            abyssRepresentations[i] = abyssRepresentation;
        }
    }