public function __construct($dataDir = null)
{
if (!isset($dataDir)) {
$r = new \ReflectionClass('Umpirsky\\Country\\Builder\\Builder');
$dataDir = sprintf('%s/../../../../country', dirname($r->getFileName()));
}
if (!is_dir($dataDir)) {
throw new \RuntimeException(sprintf('Unable to locate the country data directory at "%s"', $dataDir));
}
$this->dataDir = realpath($dataDir);
}