code: public boolean relaxPriority(E key, double priority) {
      Entry<E> entry = getEntry(key);
      if (entry == null) {
        entry = makeEntry(key);
      }
      if (compare(priority, entry.priority) <= 0) {
        return false;
      }
      entry.priority = priority;
      heapifyUp(entry);
      return true;
    }
docs: Promotes a key in the queue, adding it if it wasn't there already.  If the specified priority is worse than the current priority, nothing happens.  Faster than add if you don't care about whether the key is new.
  
  @param key an <code>Object</code> value
  @return whether the priority actually improved.