text: from djmodels.core.management.base import BaseCommand, CommandError
  
  
  class Command(BaseCommand):
      help = "Useless command."
  
      def add_arguments(self, parser):
          parser.add_argument('args', metavar='app_label', nargs='*', help='Specify the app label(s) to works on.')
          parser.add_argument('--empty', action='store_true', help="Do nothing.")
  
      def handle(self, *app_labels, **options):
          app_labels = set(app_labels)
  
          if options['empty']:
              self.stdout.write("Dave, I can't do that.")
              return
  
          if not app_labels:
              raise CommandError("I'm sorry Dave, I'm afraid I can't do that.")
  
          # raise an error if some --parameter is flowing from options to args
          for app_label in app_labels:
              if app_label.startswith('--'):
                  raise CommandError("Sorry, Dave, I can't let you do that.")
  
          self.stdout.write("Dave, my mind is going. I can feel it. I can feel it.")
  