code: func NewPriorityQueue(hint int, allowDuplicates bool) *PriorityQueue {
  	return &PriorityQueue{
  		items:           make(priorityItems, 0, hint),
  		itemMap:         make(map[Item]struct{}, hint),
  		allowDuplicates: allowDuplicates,
  	}
  }
docs: // NewPriorityQueue is the constructor for a priority queue.