{
  "arrays": [
    {"_id":"cross","items":[{"sku":"A","qty":1},{"sku":"B","qty":5}]},
    {"_id":"same","items":[{"sku":"A","qty":5}]}
  ],
  "inventory": {"_id":"stock","stock":100,"version":1},
  "deduct": {"quantity":80,"expected_version":1},
  "unique_attempts": [{"_id":"u1","tenant":"A","request_id":"pay-1"},{"_id":"u2","tenant":"A","request_id":"pay-1"}],
  "transaction_errors": [["TransientTransactionError"],["UnknownTransactionCommitResult"],[]],
  "oplog_window": {"earliest":15,"latest":40,"inside_token":20,"expired_token":12},
  "orders": {"count":10000,"tenants":10}
}