private function checkFile(string &$file): bool
    {
        $file = "{$this->directory}/{$file}";

        return file_exists($file) || (touch($file) && chmod($file, 0600));
    }
private function checkFile(string &$file): bool
    {
        $file = "{$this->directory}/{$file}";

        return file_exists($file) || (touch($file) && chmod($file, 0600));
    }
private function checkFile ( string & $ file ) : bool { $ file = "{$this->directory}/{$file}" ; return file_exists ( $ file ) || ( touch ( $ file ) && chmod ( $ file , 0600 ) ) ; }
Check file.
@param  string &$file
@return bool
Check file .