docs: def deploy_to(self, displays=None, exclude=[], lock=[]):
          """
          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.
          """
          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()