(self, spider: Spider)
return self.df.open()
(1) initialize the memory queue
        (2) initialize the disk queue if the ``jobdir`` attribute is a valid directory
        (3) return the result of the dupefilter's ``open`` method
(1) initialize the memory queue
        (2) initialize the disk queue if the ``jobdir`` attribute is a valid directory
        (3) return the result of the dupefilter's ``open`` method
( 1 ) initialize the memory queue ( 2 ) initialize the disk queue if the jobdir attribute is a valid directory ( 3 ) return the result of the dupefilter s open method
def open(self, spider: Spider) -> Optional[Deferred]:
        """
        (1) initialize the memory queue
        (2) initialize the disk queue if the ``jobdir`` attribute is a valid directory
        (3) return the result of the dupefilter's ``open`` method
        """
        self.spider = spider
        self.mqs = self._mq()
        self.dqs = self._dq() if self.dqdir else None
        return self.df.open()
def open ( self , spider : Spider ) -> Optional [ Deferred ] : self . spider = spider self . mqs = self . _mq ( ) self . dqs = self . _dq ( ) if self . dqdir else None return self . df . open ( )