title: forward protocol @required to subclasses
body: <p>I have:</p>
  
  <pre><code>@interface SuperClass : UIViewController &lt;UITableViewDelegate,UITableViewDataSource&gt;
  </code></pre>
  
  <p>And then</p>
  
  <pre><code>@interface SubClass : SuperClass
  </code></pre>
  
  <p>This <code>SuperClass</code>does not have the required protocol methods implemented <code>SubClass</code> one does.<br>
  Is it possible to prevent the warnings (saying SuperClass implementation is incomplete)?</p>
  
  <p>Instead of implementing empty/nil methods in <code>SuperClass</code>, can the @required warnings validation be made against <code>SubClass</code>?</p>