docs: def upload(self, photo_file, **kwds):
          """
          Endpoint: /photo/upload.json
  
          Uploads the specified photo filename.
          """
          with open(photo_file, 'rb') as in_file:
              result = self._client.post("/photo/upload.json",
                                         files={'photo': in_file},
                                         **kwds)["result"]
          return Photo(self._client, result)