data/cache.go
func (s *Cache) unsafeGet(key string) (*cacheItem, error) {
	v, ok := s.values[key]
	if !ok {
		return nil, raiqub.InvalidKeyError(key)
	}
	return v, nil
}
func (s *Cache) unsafeGet(key string) (*cacheItem, error) {
	v, ok := s.values[key]
	if !ok {
		return nil, raiqub.InvalidKeyError(key)
	}
	return v, nil
}
// unsafeGet gets one cacheItem instance from its key without locking.
//
// Errors:
// InvalidKeyError when requested key could not be found.