public function render( $post ) 
    {
        $old_instance = \get_post_meta( $post->ID, $this->settings['id'], true );
        $this->form->updater->update( $old_instance === "" ? array() : $old_instance );
        // Add an nonce field so we can check for it later.
        wp_nonce_field( $this->action_name(), $this->nonce_name() );
        $this->form->render(true);
    }