-- the coupons C-2 turns on --
  coupon 69   code=Sari50           D10 promotion=57       D7 refs: delta0->57, delta1->58
  coupon 54   code=CEU20            D10 promotion=54       D7 refs: delta1->54
  coupon 9    code=STATEBOARD       D10 promotion=NONE     D7 refs: none
  coupon 13   code=laurenshultz     D10 promotion=NONE     D7 refs: none

-- the intentional loss --
  rows logged: 1 (expected exactly 1)
  coupon_id=69 -> lost promotion 58 | NOT_MIGRATED | source_row JSON: 421 bytes

-- constraint checks --
  duplicate coupon codes in D10           : 0
  coupons total                           : 120 (D7: 120)
  coupons with a promotion                : 118 (D7 refs: 118 coupons)
  promotion 58 still exists               : yes
  promotion 58 coupon count (expect 0)    : 0