set up structure

src/transaction_system.cpp

@@ -0,0 +1,19 @@
+#include <cstring>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+#include <utility>
+#include "basic_defs.h"
+#include "data.h"
+#include "engine.h"
+#include "utils.h"
+
+std::string TicketSystemEngine::BuyTicket(const std::string &command) { return "BuyTicket"; }
+
+std::string TicketSystemEngine::QueryOrder(const std::string &command) { return "QueryOrder"; }
+
+std::string TicketSystemEngine::RefundTicket(const std::string &command) { return "RefundTicket"; }
+
+std::string TicketSystemEngine::QueryTransfer(const std::string &command) { return "QueryTransfer"; }
+
+std::string TicketSystemEngine::QueryTicket(const std::string &command) { return "QueryTicket"; }