docs: def get_device_model():
      """
      Returns the Device model that is active in this project.
      """
      try:
          return apps.get_model(settings.GCM_DEVICE_MODEL)
      except ValueError:
          raise ImproperlyConfigured("GCM_DEVICE_MODEL must be of the form 'app_label.model_name'")
      except LookupError:
          raise ImproperlyConfigured(
              "GCM_DEVICE_MODEL refers to model '%s' that has not been installed" % settings.GCM_DEVICE_MODEL
          )