title: Perform migration by adding List() and another model class
body: <p>I have the following models</p>
  
  <pre><code>class Area: Object {
  
  // Specify properties to ignore (Realm won't persist these)
  
  //  override static func ignoredProperties() -&gt; [String] {
  //    return []
  //  }
  
      dynamic var id = 0
      dynamic var name = ""
  
      override static func primaryKey() -&gt; String? {
          return "id"
      }
  
  }
  
  class Region: Object {
  
  // Specify properties to ignore (Realm won't persist these)
  
  //  override static func ignoredProperties() -&gt; [String] {
  //    return []
  //  }
  
      dynamic var id = 0
      dynamic var name = ""
  
      override static func primaryKey() -&gt; String? {
          return "id"
      }
  
  }
  </code></pre>
  
  <p>And I would like to add <code>let areas = List&lt;Area&gt;()</code> to Region class and <code>dynamic var region: Region?</code> to Area class, may I ask how to perform the migration block? Cause the example in the migration documentation is only demo-ing the primitive types.</p>