/**
 * Create a new instance of the class
 * @param string $classname Class to instantiate
 * @return object the instance
 * @throw FactoryException If the class is not instantiable
 */
private function newInstance($classname) {
    $reflectionClass = new \ReflectionClass($classname);
    if (! $reflectionClass->isInstantiable()) {
        throw new FactoryException("The class $classname is not instantiable.");
    }
    return new $classname;
}