def push(self, item, priority=None):
priority = item if priority is None else priority<EOL>node = PriorityQueueNode(item, priority)<EOL>for index, current in enumerate(self.priority_queue_list):<EOL><INDENT>if current.priority < node.priority:<EOL><INDENT>self.priority_queue_list.insert(index, node)<EOL>return<EOL><DEDENT><DEDENT>self.priority_queue_list.append(node)<EOL>
Push the item in the priority queue.
        if priority is not given, priority is set to the value of item.