Response error schema code generation

Hello, I am trying to generate a csharp client using Swagger 2.0 and Swagger Codegen v2.4.21.  My Swagger file describes API responses with different schemas based on status codes:

responses:
        200:
          description: "successful operation"
          schema:
            type: "array"
            items:
              $ref: "#/definitions/AppointmentAddResult"
        400:
          description: "Bad request"
          schema:
            $ref: "#/definitions/BatchAppointmentAddErrorBody"

  Models are generated for both schemas, however the model for the 400 response code is not used anywhere in the generated client.  Is this expected behavior?  I would have expected code to be generated to actually create objects based on the JSON returned with the 400 status code.  Any help would be greatly appreciated.  Thanks.