Test 4: Validating duplicate detection...
Found 7 duplicate groups:
  - John Smith: 2 duplicate(s)
  - Sarah Johnson: 1 duplicate(s)
  - Michael Brown: 1 duplicate(s)
  - Jennifer Davis: 1 duplicate(s)
  - Robert Wilson: 1 duplicate(s)
  - Lisa Anderson: 1 duplicate(s)
  - Thomas Clark: 1 duplicate(s)

✓ All expected duplicate groups found
Traceback (most recent call last):
  File "<stdin>", line 73, in <module>
KeyError: 'match_reason'