def METHOD_NAME(self) -> str:
    """Returns the JSON representation of the actual instance"""
    if self.actual_instance is None:
        return "null"
    METHOD_NAME = getattr(self.actual_instance, "to_json", None)
    if callable(METHOD_NAME):
        return self.actual_instance.METHOD_NAME()
    else:
        return json.dumps(self.actual_instance)