Eclipselink Dynamic Persistence 允许多个主键： DynamicTypeBuilder.setPrimaryKeyFields(String primarykeysField...)
但是，在 Dynamic PersistenceEntityManager.find( Entity Class , Object primaryKey)中的复合主键（Multiple Primarykey）（因为没有IdClass或EmbeddedId）的情况下，我如何通过查找实体的方法找到实体对象（实例）。
EclipseLink 在 find() 操作中获取 pk 列表，但如果示例中定义了复合 pk 键 -
Entity = Person
Fields = username,emailId,firstName,lastName
Composite PK = username,emailId
Class<?> clazz = new DynamicClassLoader(Thread.currentThread().getContextClassLoader()).createDynamicClass("Person");
DynamicTypeBuilder builder = new DynamicTypeBuilder(clazz, null, "Person");
DynamicType dynamicType = builder.getType();
builder.setPrimaryKeyFields(["username","emailId"]);
builder.addDirectMapping("username",String.class,"username");
builder.addDirectMapping("emailId",String.class,"emailId");
builder.addDirectMapping("firstName",String.class,"firstName");
builder.addDirectMapping("lastName",String.class,"lastName");
List list = new ArrayList();
list.add(${username}); //Run time value
list.add(${emailId}); //Run time value
然后EnitityManager.find(dynamicType.getJavaClass(),list)会接受这些论点，对吗？如果我假设正确，那么EnitityManager.find()操作将如何知道 List 1st 参数是 username 或 emailId pk 值（表示复合 pk 字段值的序列）而不是 Map({username:${username},emailId:${emailId}})或其他 DataStucture 。