protected function getTempnam($variation, $extention) {
	    $prefix = $this->getOption('tempnam_prefix', 'eio') . $variation;
		// tempnam() does not handle extension
		while (true) {
			$filename = sys_get_temp_dir() . DIRECTORY_SEPARATOR . $prefix . substr(md5(uniqid().rand()), 0, 8) . '.' . $extention;
			if (!is_file($filename)) {
				return $filename;
			}
		}
	}