curl -X DELETE \
 /customers/{id} \
 --header "Authorization: Bearer <token>"

{
  "type": "https://tools.ietf.org/html/rfc2616#section-10",
  "detail": "The customer could not be deleted due missing preconditions.",
  "violations": [
    {
      "propertyPath": "",
      "message": "The customer has active invoices.",
      "code": "customer_has_invoices"
    }
  ]
}