title: Can port be changed for HTMLAnchorElement?
body: <pre><code>a=document.createElement('a')
  &lt;a&gt;​&lt;/a&gt;​
  a.port="123"
  "123"
  a.port
  ""
  </code></pre>
  
  <p>Any ways to change the port? I found that the HTMLAnchorElement is using URLUtils interface. But I dont know how to figure out whether the port can be changed or not.</p>