protected function loadFile($file)
    {
        if (!stream_is_local($file)) {
            throw new \InvalidArgumentException(sprintf('Procedure file is not a local file: "%s"', $file));
        }

        if (!file_exists($file)) {
            throw new NotExistsException(sprintf('Procedure file does not exist: "%s"', $file));
        }

        return file_get_contents($file);
    }