```
rat_nreads = sorted([(self.markers2lens[m],n) for m,n in self.markers2nreads.items()],key = lambda x: x[1])
rat_nreads, removed = [], []

```

I saw this code and was really confused; what is the point of assigning `rat_nreads` to a sorted list if it's going to be assigned to an empty list right after? Does the first line actually change `self.markers2nreads.items()` in any way?