EMBER: Render div block only if component has yielded

I have the following hbs snippet:

<div class='photo-viewer-control' local-class='leftbar'>
  
</div>

I want to render the div only if leftbar has yielded.

I already tried the following:

  <div class='photo-viewer-control' local-class='leftbar'>
    
  </div>

I added the has-block but the div is still rendering when there is no leftbar.