code: def set_recovery_range(working_dir, start_block, end_block):
      
      recovery_range_path = os.path.join(working_dir, '.recovery')
      with open(recovery_range_path, 'w') as f:
          f.write('{}\n{}\n'.format(start_block, end_block))
          f.flush()
          os.fsync(f.fileno())
docs: Set the recovery block range if we're restoring and reporcessing
      transactions from a backup.
  
      Writes the recovery range to the working directory if the working directory is given and persist is True