protected function validateKey($key)
{
if (!is_string($key)) {
throw new InvalidArgumentException(sprintf('Cache key must be string, "%s" given', gettype($key)));
}
if (preg_match('|[\\{\\}\\(\\)/\\\\@\\:]|', $key)) {
throw new InvalidArgumentException(sprintf('Invalid key: "%s". The key contains one or more characters reserved for future extension: {}()/\\@:', $key));
}
}