QueryDSL获取@EllementCollection

Question

给出以下伪实体模型：

@Entity
@Table(name = "parent")
public class Parent {

    @Id
    private Long id;

    @OneToMany(mappedBy="parent")
    private List<Child> children;
}

@Entity
@Table(name = "child")
public class Child {

    @Id
    private Long id;

    @ManyToOne
    @JoinColumn(name="parent_id")
    private Parent parent;  

    @ElementCollection
    @CollectionTable(name = "child_hobby", joinColumns = @JoinColumn(name = "id"))
    private List<Hobby> hobbies;
}

public enum Hobby {
    DANCE, SING, RUN
}

一个人如何在一次提取中提取parent以及它们的children及其相应爱好的列表？

到目前为止，我尝试的是处理@OneToMany关系时通常要做的事情：

QBean<Parent> parentProjection = Projections.fields(Parent.class, QParent.parent.id);
QBean<Child> childProjection = Projections.fields(Child.class, QChild.child.id);
EnumPath<Hobby> hobbies = Expressions.enumPath(Hobby.class, "hobbies");
Map<Parent, Group> result = from(QParent.parent)
    .innerJoin(QParent.parent.children, QChild.child)
    .innerJoin(QChild.child.hobbies, hobbies);
    .transform(GroupBy.groupBy(parentProjection).as(GroupBy.list(childProjection), GroupBy.list(hobbies);

result.forEach((parent, groups) -> {
    parent.setChildren(groups.getList(childProjection));
    // How to get the hobbies of the parent's children?
});

上面的片段运行正常，但是我无法从投影组中检索child.hobbies。在QueryDSL文档的Result Aggregation部分中，我找不到任何可以帮助这种情况的信息。