title: Unrecognized selector sent to instance while adding annotation in MKMapview
body: <p>This is the error I am getting while adding annotations to <code>MKMapView</code>.</p>
  
  <p>I have also created a custom class that conforms to the <code>MKAnnotation</code> protocol with three <code>@property</code>: <code>coordinate</code>, <code>title</code> and <code>subtitle</code>.</p>
  
  <p><img src="https://i.stack.imgur.com/JKlbK.png" alt="enter image description here"></p>