private function setRestDriver($restDriver)
{
$namespace = '\\' . __NAMESPACE__ . '\\RestClient\\';
$driver = $namespace . $restDriver;
$parent = $namespace . 'DriverInterface';
if (empty($restDriver) || !class_exists($driver) || !is_subclass_of($driver, $parent)) {
throw new InvalidArgumentException('rest driver', $driver);
}
// create a new REST Driver
$this->restDriver = new $driver();
if (isset($this->url)) {
$this->restDriver->setHost($this->url);
}
}