title: Does Collections.shuffle guarantee the result is not sorted?
body: <p>Does <code>Collections.shuffle</code> guarantee the resulting list is not sorted in ascending or descending order?</p>
  
  <p>Suppose I have a list of Strings <code>letters</code> containing "a", "b", "c", "d".</p>
  
  <p>After <code>Collections.shuffle(letters)</code> will <code>letters</code> ever be equal to a-b-c-d or d-c-b-a?</p>
  
  <p>If <code>letters</code> can end up ordered, is there a way to prevent <code>Collections.shuffle</code> from leaving the list sorted in ascending or descending order?</p>