docs: def revert(context, file_names):
      """Revert each file in the list file_names back to version in repo"""
      context.obj.find_repo_type()
      if len(file_names) == 0:
          click.echo('No file names to checkout specified.')
          click.echo('The following have changed since the last check in.')
          context.invoke(status)
      for fn in file_names:
          if context.obj.vc_name == 'git':
              context.obj.call(['git', 'checkout', '--', fn])
          elif context.obj.vc_name == 'hg':
              context.obj.call(['hg', 'revert', '--no-backup', fn])