Method update

/**
 * Method to call the captcha callback if it exist.
 *
 * @param   string  $name   Callback name
 * @param   array   &$args  Arguments
 *
 * @return  mixed
 *
 * @since   4.0.0
 */
private function update($name, &$args)
{
    if (method_exists($this->captcha, $name)) {
        return call_user_func_array(array($this->captcha, $name), array_values($args));
    }
    return null;
}