title: implicit Objective-C entrypoint on updating code to swift 4
body: <p>I am getting following warning on updating my code to swift 4 </p>
  
  <blockquote>
    <p><em>implicit Objective-C entrypoint -[development.ASTodayViewController tableView:heightForHeaderInSection:] is deprecated and will be removed
    in Swift 4</em></p>
  </blockquote>
  
  <p>How to resolved that ?</p>
  
  <p>I have table delegate method as  </p>
  
  <pre><code> func tableView(_ tableView: UITableView, 
          heightForHeaderInSection section: Int) -&gt; CGFloat {
        return 40.0  
   }
  </code></pre>