title: How to use generics with JpaRepository of spring data jpa
body: <pre><code>//generic repo
  public interface MyGenericRepo extends JpaRepository&lt;GenericEntity,Integer&gt; { }
  
  //entity
  class Place extends GenericEntity {
      private Event event;
  }
  
  //entity
  class Event extends GenericEntity{  }
  
  //entity
  class Offer extends GenericEntity
  {
      private Place place;
  }
  
  //entity
  class User extends GenericEntity {
      private Place place;
  }
  </code></pre>
  
  <p>what should I take in GenericEntity and how to create a ModelManager to save and load entities</p>