import bisectclass PriorityQueue:	    def __init__(self):	self.queue = []    def append(self, data, priority):	"""Append a new element to the queue according to its priority"""	bisect.insort(self.queue, (priority, data))    def pop(self, n):	"""Pop the highest element of the queue. The n argument is	here to follow the standard queue protocol """			return self.queue.pop(0)    def contains(self, x):	return x in self.queue    def population(self):	return len(self.queue)