title: GraphQL non-nullable field nested in nullable field
body: <p>I have a GraphQL query that returns a set of notifications.  The "creator" field does not appear in every notification which is a problem because it is of type "User" and User has an "id" field that is non-nullible.  Is it possible to have non-nullible fields nested in nullable ones?</p>
  
  <pre><code>{
    myNotifications {
      id
      title
      message
      image
      creator {
        id
        full_name
      }
    }
  }
  </code></pre>