In the test code, there are times when `time.Sleep` is used to wait for processes to complete. This testing can be pass or failure.Such tests are referred to as flaky tests.Flaky tests can be very stressful and are actually a waste of time.As solutions, methods using retries or channels have been suggested.These methods involve the use of mocks, which I think are excellent for testing interfaces, but there may be cases where they are not applicable.