code: def capture_video(self, length):
          
          with self.capture_video_context() as ctx:
              time.sleep(length)
          return ctx.videofile
docs: Capture a video.
  
          This always writes to the memory card, since internal RAM is likely
          to run out of space very quickly.
  
          Currently this only works with Nikon cameras.
  
          :param length:      Length of the video to capture in seconds.
          :type length:       int
          :return:            Video file
          :rtype:             :py:class:`File`