{
  "description": "Identical id's in more than one imp element",
  "mockBidRequest": {
    "id": "some-request-id",
    "site": {
      "page": "prebid.org"
    },
    "imp": [
      {
        "id": "some-impression-id",
        "banner": {
          "format": [
            {
              "w": 300,
              "h": 250
            }
          ]
        },
        "ext": {
          "appnexus": {
            "placementId": 12883451
          }
        }
      },
      {
        "id": "some-impression-id",
        "banner": {
          "format": [
            {
              "w": 200,
              "h": 250
            }
          ]
        },
        "ext": {
          "appnexus": {
            "placementId": 10433395
          }
        }
      }
    ],
    "tmax": 500
  },
  "expectedReturnCode": 400,
  "expectedErrorMessage": "Invalid request: request.imp[0].id and request.imp[1].id are both \"some-impression-id\". Imp IDs must be unique.\n"
}