a href="#in-3">in/3</a></td><td>
  <h4><a name="Append_an_item_to_the_tail_of_a_specific_priority_queue.">Append an item to the tail of a specific priority queue.</a></h4>
  O(1).</td></tr>
<tr><td valign="top"><a href="#is_empty-1">is_empty/1</a></td><td>
  <h4><a name="Check_if_the_priority_queue_is_empty.">Check if the priority queue is empty.</a></h4>
  O(1).</td></tr>
<tr><td valign="top"><a href="#is_queue-1">is_queue/1</a></td><td>
  <h4><a name="Check_if_the_priority_queue_type_is_as_expected.">Chec