code: func SetDictionary(dict map[string]uint16) error {
  	if dict == nil {
  		return nil
  	}
  
  	for route, code := range dict {
  		r := strings.TrimSpace(route)
  
  		// duplication check
  		if _, ok := routes[r]; ok {
  			return fmt.Errorf("duplicated route(route: %s, code: %d)", r, code)
  		}
  
  		if _, ok := codes[code]; ok {
  			return fmt.Errorf("duplicated route(route: %s, code: %d)", r, code)
  		}
  
  		// update map, using last value when key duplicated
  		routes[r] = code
  		codes[code] = r
  	}
  
  	return nil
  }
docs: // SetDictionary set routes map which be used to compress route.