[Snippet rust]
```rust
async fn verify_if_merchant_reference_not_present_by_merchant_reference_id(
```
Path: hyperswitch/crates/router/src/core/customers.rs :: verify_if_merchant_reference_not_present_by_merchant_reference_id (function, crate=router)

Negatives:
- hyperswitch/crates/diesel_models/src/query/dispute.rs :: find_by_merchant_id_payment_id
- hyperswitch/crates/hyperswitch_domain_models/src/type_encryption.rs :: batch_encrypt_via_api
- hyperswitch/crates/hyperswitch_connectors/src/connectors/fiserv.rs :: get_content_type
- hyperswitch/crates/drainer/src/lib.rs :: start_drainer
- hyperswitch/crates/router/src/db/kafka_store.rs :: update_payout