code: def send_video(self, chat_id, video, duration=None, caption=None, reply_to_message_id=None, reply_markup=None):
          
          payload = dict(chat_id=chat_id,
                         duration=duration,
                         caption=caption,
                         reply_to_message_id=reply_to_message_id,
                         reply_markup=reply_markup)
          files = dict(video=open(video, 'rb'))
          return Message.from_api(api, **self._post('sendVideo', payload, files))
docs: Use this method to send video files, Telegram clients support mp4 videos (other formats may be sent as
              Document). On success, the sent Message is returned. Bots can currently send video files of up to 50 MB
              in size, this limit may be changed in the future.