title: Realm: While writing a new object, how can I avoid creating an object for a relation?
body: <p>In Realm, what's the right way of creating a new object, without creating a new object for one of its relations?</p>
  
  <p>Let's say I have the object <code>Person</code> with a one-to-one relation to the <code>Job</code> entity.</p>
  
  <p>My code writes first 10 <code>Jobs</code> objects and then creates 10 other <code>Person</code> objects with the previously created objects. </p>
  
  <p>Since the <code>Person</code> didn't exist before, the flag for <code>update</code> is false. </p>
  
  <pre><code>realm.add(person, update: false)
  </code></pre>
  
  <p>But since the <code>Job</code> object already existed it throws the follow exception:</p>
  
  <blockquote>
    <p>Terminating app due to uncaught exception 'RLMException'.'Can't set
    primary key property '' to existing value ''.'</p>
  </blockquote>