title: Changing the priority of an element in a PriorityQueue
body: <p>I know that <code>PriorityQueue</code> automatically sorts the elements when <code>add()</code>ing one by using the objects' <code>compareTo()</code> method. Let's say I want to change the priority of an element in the queue at some point. How do I explicitly order the <code>PriorityQueue</code> to sort itself again, given that the priority of an element has changed?</p>