title: unmarshalling nested complex object using rdf:about
body: <p>I'm having trouble unmarshalling nested complex object. In below xml example "Racing" has a RacingTicket obj. That can be reached by the rdf:about link, which is a restful service call to get RacingTicket.   </p>
  
  <pre><code>&lt;?xml version='1.0' encoding='UTF-8'?&gt;
  &lt;entry xmlns="http://www.w3.org/2005/Atom" xmlns:hl="http://racing.com/horses/holding-location"&gt;
      &lt;title type="text"&gt;Create Racing Event&lt;/title&gt;
      &lt;id&gt;http://www.racing.com/&lt;/id&gt;
      &lt;content type="application/xml"&gt;
      &lt;racing xmlns="http://racing.com/schema/horses"&gt;
          &lt;racingTicket rdf:about="https://racing.com/fast/racingTicket/asdf-asfd-asdf-asdf-asdf" /&gt;
          &lt;tracks&gt;
          &lt;track&gt;
              &lt;title&gt;ABX&lt;/title&gt;
              &lt;amount&gt;560&lt;/amount&gt;
          &lt;/track&gt;
          &lt;/tracks&gt;
          &lt;racingId&gt;001&lt;/racingId&gt;
      &lt;/racing&gt;
      &lt;/content&gt;
  &lt;/entry&gt;
  
  
  
  Java class
  
  @XmlRootElement
  public class Racing implements Serializable {
  
      @AtomId( prefixUrl = "http://racing.com/fast/racingTicket/" )
      private String id;
  
      private RacingTicket racingTicket;
  
      private Tracks tracks;
  
      private BigDecimal racingId;
  
  
  
      public RacingTicket getRacingTicket() {
  
      return racingTicket;
      }
  
      @XmlElement
      public void setRacingTicket( RacingTicket racingTicket ) {
  
      this.racingTicket = racingTicket;
      }
  </code></pre>
  
  <p>The object returned by jaxb unmarshaler contains all values as null for racingTicket class. 
  Please advise, any help appreciated.  </p>