title: How to change the NSPopover's arrow head position?
body: <p>I have a NSPopover on my app but i want to change the position of the arrow head.
  <br>What i have: <br><img src="https://i.stack.imgur.com/ufJf9.png" alt="enter image description here"></p>
  
  <p><br>What i want:<br>
  <img src="https://i.stack.imgur.com/DdYdZ.png" alt="enter image description here"></p>
  
  <p><br>As you can see in the second image the arrow head of the NSPopover is at the top.
  How can i do that?
  <br>my code: </p>
  
  <pre><code>[_popover showRelativeToRect:[sender bounds] ofView:sender preferredEdge:NSMaxXEdge];
  </code></pre>
  
  <p>Thank you!</p>