Method on_connection_open

cpp/src/context_test.cpp:109–122

    }

    void on_connection_open(proton::connection& c) override {
        // Get default session
        proton::session s = c.default_session();

        std::string data_ssn = "session-user-data";
        // Set user context 'data' on default session.
        s.user_data(&data_ssn);
        ASSERT_EQUAL(&data_ssn, s.user_data());

        std::string data_con = "connection-user-data";
        // Set user context 'data' on current connection.
        c.user_data(&data_con);
        ASSERT_EQUAL(&data_con, c.user_data());
    }

    void on_sendable(proton::sender &s) override {
        proton::message msg;