code: def deploy_to(self, displays=None, exclude=[], lock=[]):
          
          if displays is None:
              signs = Sign.objects.all()
          else:
              signs = Sign.objects.filter(display__in=displays)
          for sign in signs.exclude(display__in=exclude):
              sign.pages.add(self)
              sign.save()
docs: Deploys page to listed display (specify with display). If display is None,
          deploy to all display. Can specify exclude for which display to exclude.
          This overwrites the first argument.