code: def load_paired_notebook(notebook, fmt, nb_file, log):
      
      formats = notebook.metadata.get('jupytext', {}).get('formats')
  
      if not formats:
          raise ValueError("'{}' is not a paired notebook".format(nb_file))
  
      max_mtime_inputs = None
      max_mtime_outputs = None
      latest_inputs = None
      latest_outputs = None
      for alt_path, alt_fmt in paired_paths(nb_file, fmt, formats):
          if not os.path.isfile(alt_path):
              continue
          info = os.lstat(alt_path)
          if not max_mtime_inputs or info.st_mtime > max_mtime_inputs:
              max_mtime_inputs = info.st_mtime
              latest_inputs, input_fmt = alt_path, alt_fmt
  
          if alt_path.endswith('.ipynb'):
              if not max_mtime_outputs or info.st_mtime > max_mtime_outputs:
                  max_mtime_outputs = info.st_mtime
                  latest_outputs = alt_path
  
      if latest_outputs and latest_outputs != latest_inputs:
          log("[jupytext] Loading input cells from '{}'".format(latest_inputs))
          inputs = notebook if latest_inputs == nb_file else readf(latest_inputs, input_fmt)
          check_file_version(inputs, latest_inputs, latest_outputs)
          log("[jupytext] Loading output cells from '{}'".format(latest_outputs))
          outputs = notebook if latest_outputs == nb_file else readf(latest_outputs)
          combine_inputs_with_outputs(inputs, outputs, input_fmt)
          return inputs, latest_inputs, latest_outputs
  
      log("[jupytext] Loading notebook from '{}'".format(latest_inputs))
      if latest_inputs != nb_file:
          notebook = readf(latest_inputs, input_fmt)
      return notebook, latest_inputs, latest_outputs
docs: Update the notebook with the inputs and outputs of the most recent paired files