#vulnerable code 
                                public Object doGenerate(Parameterizable parameterizedType) {
        List returnedList = (List) RandomFactory.getRandomValue(parameterizedType.getType());
        returnedList.clear();
        CollectionHelper.buildCollections(returnedList, parameterizedType.getParameterTypes().get(0));
        return returnedList;
    } 
                            #location 3 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                public Object doGenerate(Parameterizable parameterizedType) {
        return CollectionHelper.buildCollections((Collection) doGenerate(parameterizedType.getType()), parameterizedType.getParameterTypes()
                .get(0));
    }