code: def page_up(self, n=1, interval=0, pre_dl=None, post_dl=None):
          
          self.delay(pre_dl)
          self.k.tap_key(self.k.page_up_key, n, interval)
          self.delay(post_dl)
docs: Pres page_up key n times.
  
          **中文文档**
  
          按 page_up 键n次。