code: def get_invitation_model():
      
      path = app_settings.INVITATION_MODEL
      try:
          return django_apps.get_model(path)
      except ValueError:
          raise ImproperlyConfigured(
              "path must be of the form 'app_label.model_name'"
          )
      except LookupError:
          raise ImproperlyConfigured(
              "path refers to model '%s' that\
               has not been installed" % app_settings.INVITATION_MODEL
          )
docs: Returns the Invitation model that is active in this project.