def description(self) -> str:
        """
        Short description.
        """
        if self.is_parent and self.is_child:
            desc = "parent+child"
        elif self.is_parent:
            desc = "parent"
        elif self.is_child:
            desc = "child"
        else:
            desc = "standalone"
        if self.circular:
            desc += "+CIRCULAR({})".format(self.circular_description)
        return desc
Short description.