A unit test sees the System Under Test (SUT) as a black box. That means that it doesn’t matter what the code inside the class or function looks like, it only matters how it manipulates the data. And the way you judge that is only by the data that goes in and out of the function. Never ever ever by looking at the code. There are four ways that you send and receive data with. 1. The in-parameters of the function you are testing. 2. The return value from the function you are testing. 3. The parameters that are used in internal calls to functions outside your SUT. The data…