code: func (s *Session) String(key string) string {
  	s.RLock()
  	defer s.RUnlock()
  
  	v, ok := s.data[key]
  	if !ok {
  		return ""
  	}
  
  	value, ok := v.(string)
  	if !ok {
  		return ""
  	}
  	return value
  }
docs: // String returns the value associated with the key as a string.