1 00:00:00,360 --> 00:00:03,760 Sum is a very simple program, that only does one thing, 2 00:00:03,760 --> 00:00:07,540 summing two number, adding two numbers. So the answer in this 3 00:00:07,540 --> 00:00:10,640 case, it's one. There's only one feature that we can test 4 00:00:10,640 --> 00:00:14,060 in PrintSum. So let's look at the slightly more interesting example.