[csharp] Multiple response types not supported

Description

When multiple responses are present in a v3 OpenAPI document with differing types, only the first one is respected when C# client SDK is generated.

openapi-generator version

3.3.3

OpenAPI declaration file content or url

  /my/api/path:
    get:
      responses:
        '200':
          content:
            application/json:
              schema:
                type: array
                items:
                  type: string
                  format: byte
        '202':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Microsoft.OpenApi.Services.AutoRestService.ServiceFault'

Command line used for generation

openapi-generator generate -g csharp -i .\openapi.json -o .\output

Related issues/PRs

I see similar issues for other languages, but perhaps C# isn't enhanced yet?

• PHP: https://github.com/OpenAPITools/openapi-generator/issues/125
• Spring: https://github.com/OpenAPITools/openapi-generator/issues/1096

Start with the supplied OpenAPI declaration and the openapi-generator generate -g csharp command, then trace how the C# generator handles multiple response schemas. Done means the generated client represents both the 200 array response and the 202 ServiceFault response instead of respecting only the first response.