即使使用initializeAndUnproxy也会抛出LazyInitializationException

Question

我需要帮助理解我在Hibernate中观察到的以下行为。

，我现在可以通过添加'hack'来使代码正常工作，所以我想删除它。

实体类：

Department.java
    - Long departmentId; (Id of department) 
    - String departmentName; (Name of department)

    @OneToOne(fetch = FetchType.LAZY)
    - Account account; (department account)


Account.java
    @ElementCollection(fetch=FetchType.LAZY)
    @CollectionTable(name="ACCOUNTS_BATCHES")
    - Set<Long> batches;

    @ElementCollection(fetch=FetchType.LAZY)
    @CollectionTable(name="ACCOUNTS_SECTIONS")
    - Set<Long> sections;


Since the fetchType is defined as Lazy, I had to do HibernateUtils.initializeAndUnproxy(), so my code is like this:

Line 1: Account account = HibernateUtils.initializeAndUnproxy((department.getAccount());

Line 2: map.put("batches", HibernateUtils.initializeAndUnproxy(account.getBatches()));       
Line 3: account.getBatches().size();

Line 4: map.put("sections", HibernateUtils.initializeAndUnproxy(account.getSections())); 
Line 5: account.getSections().size();

I only need to pass the ids of batches and sections on UI.
This works fine, but to make it work I had to explicitly add Line 3 and Line 5 (where we are doing .size())
If I remove Line 3 and Line 5, then it throws LazyInitializationException. 

My question is that why it doesn't work without adding these 2 lines and when we add it, what is happening in these 2 lines which is making it work.
Set is of type java.util.Set