Test 4: Validating duplicate detection...
Found 5 duplicate groups:
  - John Smith: 3 duplicate(s)
  - Alice Johnson: 2 duplicate(s)
  - A. J.: 4 duplicate(s)
  - Charles Lee: 3 duplicate(s)
  - David Williams: 3 duplicate(s)
WARNING: 'John Smith' has 3 duplicates, expected 2
ERROR: Expected duplicate group for 'Sarah Johnson' not found
ERROR: Expected duplicate group for 'Michael Brown' not found
ERROR: Expected duplicate group for 'Jennifer Davis' not found
ERROR: Expected duplicate group for 'Robert Wilson' not found
ERROR: Expected duplicate group for 'Lisa Anderson' not found

ERROR: Missing 5 expected duplicate groups