{
  "clients": [
    { "id": 1, "name": "Client 1" },
    { "id": 2, "name": "Client 2" }
  ],
  "serial_numbers": [
    { "id": 1, "serial_number": "SN001", "client_id": 1 },
    { "id": 2, "serial_number": "SN002", "client_id": 2 }
  ]
}