fresh?

# File actionpack/lib/action_controller/request.rb, line 126
    def fresh?(response)
      case
      when if_modified_since && if_none_match 
        not_modified?(response.last_modified) && etag_matches?(response.etag) 
      when if_modified_since 
        not_modified?(response.last_modified) 
      when if_none_match 
        etag_matches?(response.etag) 
      else 
        false 
      end 
    end