title: ObservableCollection does not raise property changed with Fody
body: <p>I have defined this class</p>
  
  <pre><code>[ImplementPropertyChanged]
  public class ChatInfo : IMessageData
  {
      public ObservableCollection&lt;Message&gt; messages { get; set; }
  
      [JsonIgnore]
      public Message LastMessage
      {
          get
          {
              return messages.Last();
          }
      }
  }
  </code></pre>
  
  <p>The class is deserialized via JSON.NET(James King) and then after I manually pushing new items to <code>messages</code>. The <code>LastMessage</code> property is bound to a view, but even if <code>messages</code> collection changes, <code>LastMessage</code> getter is not called. When I set <code>messages</code> to new collection every time, everything works fine, why doesn't <code>LastMessage</code> react to collection changed events from <code>ObservableCollection</code>?</p>