def get_subclasses(cls) -> Iterator[Type['_Transformable']]:
        """Recursively get all subclasses of :class:`_Transformable`.

        :yields: each subclass of :class:`_Transformable`.
        """
        for subclass in cls.__subclasses__():
            yield from subclass.get_subclasses()
            yield subclass
Recursively get all subclasses of :class:`_Transformable`.

        :yields: each subclass of :class:`_Transformable`.
        
patroni/postgresql/validator.py