public function autoload($className)
    {
        if (0 === strpos($className, $this->prefix)) {
            $parts = explode('\\', substr($className, $this->prefixLength));
            $filepath = $this->directory.DIRECTORY_SEPARATOR.implode(DIRECTORY_SEPARATOR, $parts).'.php';

            if (is_file($filepath)) {
                require $filepath;
            }
        }
    }