code: def create_symlink_job(directory, checksums, filetype, symlink_path):
      
      pattern = NgdConfig.get_fileending(filetype)
      filename, _ = get_name_and_checksum(checksums, pattern)
      local_file = os.path.join(directory, filename)
      full_symlink = os.path.join(symlink_path, filename)
      return DownloadJob(None, local_file, None, full_symlink)
docs: Create a symlink-creating DownloadJob for an already downloaded file.