Raised if request.node is required but not present. For example, this can be raised by philo.views.node_view(). MIDDLEWARE_NOT_CONFIGURED is an instance of django.core.exceptions.ImproperlyConfigured.
Raised by View.reverse() when the View does not provide subpaths (the default).
Raised by View.reverse() when the View can not provide a subpath for the supplied arguments.
Raised by TreeEntity.get_path() if the root instance is not an ancestor of the current instance.