title: Is there an API method that compares contents of a Seq irrespective of order?
body: <p>Assuming:</p>
  
  <pre><code>val l1 = List(1,2,3) 
  val l2 = List(2,3,1)
  </code></pre>
  
  <p>I want a method that confirms that l1 is equal to l2 (as in same contents but different order). Is there an API method on List/Seq to do this?</p>
  
  <pre><code>l1.sameElements(l2)
  </code></pre>
  
  <p>does not work as it verifies order as well.</p>
  
  <p>I've come up with the following:</p>
  
  <pre><code>l1.foldLeft(l1.size == l2.size)(_ &amp;&amp; l2.contains(_))
  </code></pre>
  
  <p>Is there anything more succinct than the above to do this comparison?</p>