'Similar to get_model(), but doesn\'t require that an app exists with
the given app_label.
It\'s safe to call this method at import time, even while the registry
is being populated.'

def get_registered_model(self, app_label, model_name):

    model = self.all_models[app_label].get(model_name.lower())
    if (model is None):
        raise LookupError(("Model    '%s.%s'    not    registered." % (app_label, model_name)))
    return model
