[Spring Server] "default" response gets mapped to 200

Description

The documentations states that the default keyword can be used to describe errors collectively:

“Default” means this response is used for all HTTP codes that are not covered individually for this operation.

But the outcome for a spring server links my Error class to a 200 code.

@ApiOperation(value = "Obtém as unidades operacionais da empresa", nickname = "findOperUnits", notes = "Retorna as unidades operacionais (estações de tratamento) mantidas no [CESANLims](http://cesanlims.sistemas.cesan.com.br:8080/cesanlims/). Valores ausentes ou vazios são suprimidos.", response = OperUnit.class, tags={ "oper-units", })
    @ApiResponses(value = { 
        @ApiResponse(code = 200, message = "successful operation", response = OperUnit.class),
        @ApiResponse(code = 200, message = "unexpected error", response = Error.class) })
    
    @RequestMapping(value = "/oper-units",
        produces = { "application/json" }, 
        method = RequestMethod.GET)
    ResponseEntity<?> findOperUnits(@ApiParam(value = "Nome da unidade operacional (`LIKE '%name%'`)") @Valid @RequestParam(value = "name", required = false) String name,@ApiParam(value = "ID da unidade organizacional responsável (vide [api-estorg](http://api-estorg.sistemas.cesan.com.br:8081/v1/swagger-ui.html))") @Valid @RequestParam(value = "orgUnitId", required = false) Integer orgUnitId,@ApiParam(value = "Label identificador da unidade operacional") @Valid @RequestParam(value = "label", required = false) String label,@ApiParam(value = "", allowableValues = "ETA, ETE") @Valid @RequestParam(value = "segment", required = false) String segment,@ApiParam(value = "Subdivisão administrativa (não é parâmetro `LIKE`)") @Valid @RequestParam(value = "system", required = false) String system,@ApiParam(value = "", allowableValues = "active, inactive") @Valid @RequestParam(value = "status", required = false) String status);

Since there's a 200 response described within the operation, shouldn't the error class be related to something else?

Swagger-codegen version

swagger-codegen-cli-3.0.0-SNAPSHOT

Swagger declaration file content or url

openapi: "3.0.0"
(...)
      responses:
        '200':
          description: successful operation
          content:
            application/json:    
              schema:
                $ref: '#/components/schemas/OperUnit'
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"

Command line used for generation

java -jar swagger-codegen.jar generate -i ../../openapi.yaml -l spring -o ../..

Steps to reproduce

Related issues/PRs

Suggest a fix/enhancement

Run the provided swagger-codegen command with the shown OpenAPI responses and inspect the generated Spring server's @ApiResponses output. Trace how the default response is mapped, then verify that the Error schema is no longer associated with HTTP 200 while the explicit 200 response remains unchanged.