Method extend

examples/demo.php:4124–4124

* @param string $driver * @param \Closure $callback * @param-closure-this $this $callback * @return $this */

(string $driver, \Closure $callback)

     * @return $this
     */
    public function extend(string $driver, \Closure $callback): self { return $this; }
}

class ScaffoldingFirstClassCallable