title: How to declare JPARepository on the basis of a composite ID?
body: <p>I have a class with 2 ids like this </p>
  
  <pre><code>@Entity
  @IdClass(PersonID.class)
  public class Person{
     @Id
     private int id;
     @Id
     private int flag;
  
     ...
  }
  public class PersonID{
     int id;
     int flag;
  }
  </code></pre>
  
  <p>I want to use <code>JPARepository&lt;Person,???&gt;</code> to use his methods but i don't now how !!</p>