code: def get_subreddit_image(self, subreddit, id):
          
          url = self._base_url + "/3/gallery/r/{0}/{1}".format(subreddit, id)
          resp = self._send_request(url)
          return Gallery_image(resp, self)
docs: Return the Gallery_image with the id submitted to subreddit gallery
  
          :param subreddit: The subreddit the image has been submitted to.
          :param id: The id of the image we want.