15std::chrono::system_clock::time_point MockNow()
noexcept;
16std::chrono::steady_clock::time_point MockSteadyNow()
noexcept;
17void MockNowSet(std::chrono::system_clock::time_point new_mocked_now);
18void MockSleep(std::chrono::seconds duration);
19void MockSleep(std::chrono::milliseconds duration);