title: time.Millisecond * int confusion
body: <p>In the below example, if the 1000's are both int's (which I think they are) why would the bottom fail to compile?</p>
  
  <pre><code>//works
  time.Sleep(1000 * time.Millisecond)
  
  //fails
  var i = 1000
  time.Sleep(i * time.Millisecond)
  </code></pre>