In the solution of “Rotate a Linked List” from python learning path. There’s a function I don’t quite understand:

```
def adjust_rotations_needed(n, length):
# If n is positive then number of rotations performed is from right side
# and if n is negative then number of rotations performed from left side
# Let's optimize the number of rotations.
# Handle case if 'n' is a negative number.
n = n % length
if n < 0:
n = n + length
```

If I have n as -9, and length is 7, before hitting “if n<0”, n will be (-9) %7 = 5.

My question is, in what circumstance that the program will hit “if n< 0:” line?

Thanks.