code: def poll(self):
          '''check for events, returning one event'''
          if self.out_queue.qsize() <= 0:
              return None
          evt = self.out_queue.get()
          while isinstance(evt, win_layout.WinLayout):
              win_layout.set_layout(evt, self.set_layout)
              if self.out_queue.qsize() == 0:
                  return None
              evt = self.out_queue.get()
          return evf poll(self):
          '''check for events, returning one event'''
          if self.out_queue.qsize() <= 0:
              return None
          evt = self.out_queue.get()
          while isinstance(evt, win_layout.WinLayout):
              win_layout.set_layout(evt, self.set_layout)
              if self.out_queue.qsize() == 0:
                  return None
              evt = self.out_queue.get()
          return evt
docs: check for events, returning one event