#vulnerable code 
                                public <T> Collection<T> loadAll(Collection<T> objects, SortOrder sortOrder, Pagination pagination, int depth) {

        if (objects == null || objects.isEmpty()) {
            return objects;
        }

        Set<Serializable> ids = new LinkedHashSet<>();
        Class type = objects.iterator().next().getClass();
        ClassInfo classInfo = session.metaData().classInfo(type.getName());
        for (Object o : objects) {
            FieldInfo idField;
            if (classInfo.hasPrimaryIndexField()) {
                idField = classInfo.primaryIndexField();
            } else {
                idField = classInfo.identityField();
            }
            ids.add((Serializable) idField.readProperty(o));
        }
        return session.loadAll(type, ids, sortOrder, pagination, depth);
    } 
                            #location 12 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                public <T> Collection<T> loadAll(Collection<T> objects, SortOrder sortOrder, Pagination pagination, int depth) {

        if (objects == null || objects.isEmpty()) {
            return objects;
        }

        ClassInfo commonClassInfo = findCommonClassInfo(objects);

        Set<Serializable> ids = new LinkedHashSet<>();
        for (Object o : objects) {
            FieldInfo idField;
            if (commonClassInfo.hasPrimaryIndexField()) {
                idField = commonClassInfo.primaryIndexField();
            } else {
                idField = commonClassInfo.identityField();
            }
            ids.add((Serializable) idField.readProperty(o));
        }
        return session.loadAll((Class<T>) commonClassInfo.getUnderlyingClass(), ids, sortOrder, pagination, depth);
    }