code: def download_file(self, filename, timeout=5):
          
          path_file = os.path.join(self.output_directory, DOWNLOADS_PATH, self.session_id[-8:], filename)
          file_url = '{}/download/{}/{}'.format(self.server_url, self.session_id, filename)
          # download the file
          if self.browser_remote:
              self.__download_file(file_url, path_file, timeout)
              return path_file
          return None
docs: download a file from remote selenoid and removing the file in the server.
          request: http://<username>:<password>@<ggr_host>:<ggr_port>/download/<ggr_session_id>/<filename>
          :param filename: file name with extension to download
          :param timeout: threshold until the video file is downloaded
          :return: downloaded file path or None