title: Usage of isLoaded(Object) method in PersistenceUnitUtil
body: <p>I wonder what is the reason of calling method <code>PersistenceUnitUtil#isLoaded(Object)</code>. </p>
  
  <p><a href="http://docs.oracle.com/javaee/6/api/javax/persistence/PersistenceUnitUtil.html" rel="nofollow">JPA Documentation</a> says that it can help to determine the load state of an entity belonging to persistence unit, but it also mentions that</p>
  
  <blockquote>
    <p>An entity is considered loaded if all attributes for which
    FetchType.EAGER has been specified have been loaded.</p>
  </blockquote>
  
  <p>So, are there situations when not all attributes with <code>FetchType.EAGER</code> are loaded? What are they? I am only sure that it will work for entities returned by <code>EntityManager#getReference()</code> method. Are there more of them?</p>