title: Fail to enable CORS for API Gateway functions
body: <p>I get </p>
  
  <p><a href="https://i.stack.imgur.com/WzSrf.png" rel="noreferrer"><img src="https://i.stack.imgur.com/WzSrf.png" alt="enter image description here"></a></p>
  
  <p>While attempting to enable CORS on API Gateway, why is that and how do I resolve this? These functions are deployed using AWS SAM. But I notice if I create my own APIs via AWS Console this happens too</p>
  
  <p>The errors looks like: </p>
  
  <ul>
  <li>invalid model name specified application/json=Empty </li>
  <li>invalid response status code specified</li>
  </ul>
  
  <hr>
  
  <p>I found I seem to need to add an "Empty" response model myself? </p>
  
  <hr>
  
  <p>Now, I get </p>
  
  <blockquote>
    <p>Add Access-Control-Allow-Origin Integration Response Header Mapping to POST method (invalid response status code specified)</p>
  </blockquote>
  
  <p>How do I resolve this? </p>