title: No visible @interface for ____ declares the selector
body: <p>I have set up a method in a separate class (called ExternalClass) that needs to take two arguments. </p>
  
  <pre><code>-(void) openImage:(NSDictionary *)payload InApp:(UIApplication *)app;
  </code></pre>
  
  <p>In my AppDelegate.m, I call the method like this:</p>
  
  <pre><code> - (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)payload fetchCompletionHandler (void (^)(UIBackgroundFetchResult))completionHandler
      {
          [[ExternalClass sharedInstance] openImage:payload InApp:application];
      }
  </code></pre>
  
  <p>I am getting "No visible @interface for ExternalClass declares the selector 'openImage:InApp'</p>
  
  <p>Any idea why?</p>