title: Jackson2 many to many deserialization
body: <p>I have two classes Events and Users which have a many to many relationship. </p>
  
  <pre><code>public class Event {
  
      private int id;
  
    private List&lt;Users&gt; users;
  }
  
  public class User {
          private int id;
  
        private List&lt;Event&gt; events;
  }
  </code></pre>
  
  <p>I have read @JsonIdentityInfo annotation is supposed to help but I cannot see an example of this. </p>