TEST(alarm, checkAlarmAfter10Minutes) {
  time_fake t; // implements the time_interface
  output_fake o; // implements the output interface
  alarm_clock alarm(t, o);
  
  auto ring_time = t.now() + 10min;
  clock.set_alarm(ring_time);
  
  t = t.now() + 10min; // We can increase our time
  EXPECT_EQ(o.value(), "Alarm\n"); // We can check the output
}