new_contents: import qmk
  import utils
  
  class RotateNCommand(qmk.Command):
      '''Perform a Caesar cipher and return the result.'''
      def __init__(self):
          self._name = 'rotate-n'
          self._help = self.__doc__
  
      @qmk.Command.actionRequiresArgument
      def action(self, arg):
          qmk.Message()(utils.rotn(arg))
  
  def commands(): return [ RotateNCommand() ]
  
subject: Add rotate-n command.