def get_subscriber_model(self):
        """
        Attempt to pull settings.DJSTRIPE_SUBSCRIBER_MODEL.

        Users have the option of specifying a custom subscriber model via the
        DJSTRIPE_SUBSCRIBER_MODEL setting.

        This methods falls back to AUTH_USER_MODEL if DJSTRIPE_SUBSCRIBER_MODEL is not set.

        Returns the subscriber model that is active in this project.
        """
        model_name = self.get_subscriber_model_string()

        # Attempt a Django 1.7 app lookup
        try:
            subscriber_model = django_apps.get_model(model_name)
        except ValueError:
            raise ImproperlyConfigured(
                "DJSTRIPE_SUBSCRIBER_MODEL must be of the form 'app_label.model_name'."
            )
        except LookupError:
            raise ImproperlyConfigured(
                f"DJSTRIPE_SUBSCRIBER_MODEL refers to model '{model_name}' "
                "that has not been installed."
            )

        if (
            "email"
            not in [field_.name for field_ in subscriber_model._meta.get_fields()]
        ) and not hasattr(subscriber_model, "email"):
            raise ImproperlyConfigured(
                "DJSTRIPE_SUBSCRIBER_MODEL must have an email attribute."
            )

        return subscriber_model

        Attempt to pull settings.DJSTRIPE_SUBSCRIBER_MODEL.

        Users have the option of specifying a custom subscriber model via the
        DJSTRIPE_SUBSCRIBER_MODEL setting.

        This methods falls back to AUTH_USER_MODEL if DJSTRIPE_SUBSCRIBER_MODEL is not set.

        Returns the subscriber model that is active in this project.
        
djstripe/settings.py