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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def capture_video(self, length):
 """ 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` """

        with self.capture_video_context() as ctx:
            time.sleep(length)
        return ctx.videofile