def push_slot(self, slot, obj, priority):
        """ Push an object to a priority queue for this slot """
        if slot not in self.pqueues:
            self.pqueues[slot] = self.pqfactory()
        queue = self.pqueues[slot]
        queue.push(obj, priority)
 Push an object to a priority queue for this slot 
stackoverflow/venv/lib/python3.6/site-packages/scrapy/pqueues.py