code: func ParseRequestCacheControl(value string) (*RequestCacheDirectives, error) {
  	cd := &RequestCacheDirectives{
  		MaxAge:   -1,
  		MaxStale: -1,
  		MinFresh: -1,
  	}
  
  	err := parse(value, cd)
  	if err != nil {
  		return nil, err
  	}
  	return cd, nil
  }
docs: // LOW LEVEL API: Parses a Cache Control Header from a Request into a set of directives.