#vulnerable code 
                                public Object doGenerate(final Class<?> type) {
        PojoClass pojoClass = PojoClassFactory.getPojoClass(type);

        PojoMethod valuesPojoMethod = null;
        for (PojoMethod pojoMethod : pojoClass.getPojoMethods()) {
            if (pojoMethod.getName().equals("values")) {
                valuesPojoMethod = pojoMethod;
                break;
            }
        }
        Enum<?>[] values = (Enum<?>[]) valuesPojoMethod.invoke(null, (Object[]) null);
        return values[RANDOM.nextInt(values.length)];
    } 
                            #location 11 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                public Object doGenerate(final Class<?> type) {
        PojoClass pojoClass = PojoClassFactory.getPojoClass(type);

        Enum<?>[] values = getValues(pojoClass);
        if (values == null) {
            throw RandomGeneratorException.getInstance(MessageFormatter.format("Failed to enumerate possible values of Enum [{0}]", type));
        }

        return values[RANDOM.nextInt(values.length)];
    }