The Mixed cleanup preset contains Pear with leading spaces, apple twice, Apple once, one empty line, banana with trailing spaces, item10 and item2. It enables trimming, blank removal, ignore-case deduplication and natural ascending order. These choices form the same executable tuple used by the product contract and browser test.
Two lines change at their edges
Trimming changes ` Pear` to `Pear` and `banana ` to `banana`. No internal content changes, so the trimmed-lines counter is 2. The empty line remains empty. At this stage all eight physical input lines still exist; only two string values differ from the normalized source.
One blank and two duplicates disappear
Blank removal drops the one empty row. Ignore-case deduplication keeps the first apple and removes the later Apple and final apple because all three share the lowercase key `apple`. Pear, banana, item10 and item2 remain distinct. Seven nonblank rows therefore become five unique rows, with counters 1 blank and 2 duplicates.
Natural order places item2 before item10
English natural ascending order produces apple, banana, item2, item10, Pear. The surviving spelling apple comes from the first occurrence; sorting happens only after that representative is chosen. The final reconciliation is 8 input lines, 5 output lines, 2 duplicates removed, 1 blank removed and 2 lines trimmed.