In this case I do need it because ```lines[i-1]``` is the last line in the file when ```i = 0```  (which is a TOTAL line). I could introduce an ```old``` variable as I do in the function being tested but then the test and function would be very similar (perhaps defeating the point of testing). Though this second ```if``` statement adds another branch of control flow at every iteration, it is only executed 4 times within this test, so I am compelled to leave it be.