WP_REST_Post_Meta_Fields example

    public function __construct( $post_type ) {
        $this->post_type = $post_type;
        $obj             = get_post_type_object( $post_type );
        $this->rest_base = ! empty( $obj->rest_base ) ? $obj->rest_base : $obj->name;
        $this->namespace = ! empty( $obj->rest_namespace ) ? $obj->rest_namespace : 'wp/v2';

        $this->meta = new WP_REST_Post_Meta_Fields( $this->post_type );
    }

    /** * Registers the routes for posts. * * @since 4.7.0 * * @see register_rest_route() */
    public function register_routes() {