text: #ifndef QUERYRESPONSE_H
  #define QUERYRESPONSE_H
  
  #include "Result.h"
  
  namespace ai {
      namespace query {
          namespace request {
              class QueryRequest;
          }
  
          namespace response {
              class Response
              {
              public:
                  const std::string identifier;
                  const std::string timestamp;
                  const Result result;
  
                  virtual ~Response();
  
                  friend std::ostream& operator << (std::ostream& os, const Response& query_response);
  
                  friend class ai::query::request::QueryRequest;
  
              private:
                  Response(const std::string identifier, const std::string timestamp, const Result result);
              };
  
              std::ostream& operator << (std::ostream& os, const Response& query_response);
          }
      }
  }
  
  #endif // QUERYRESPONSE_H
  