xists( $class ) ) {
			return null;
		}

		if ( ! is_subclass_of( $class, WP_REST_Controller::class ) ) {
			return null;
		}

		if ( ! $this->rest_controller ) {
			$this->rest_controller = new $class( $this->name );
		}

		if ( ! ( $this->rest_controller instanceof $class ) ) {
			return null;
		}

		return $this->rest_controller;
	}
}