Test 4: Validating duplicate detection...
Found 4 duplicate groups:
  - J. Smith: 2 duplicate(s)
  - Jane Doe: 1 duplicate(s)
  - Peter Jones: 1 duplicate(s)
  - Susan White: 1 duplicate(s)
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