[Python] - swagger flask / connexion- server - Error handling documentation

Description

I am having a hard time working in the error handling for the swagger server stub.
First of all, I was creating a server stub.

I have a pet, in my API lets say. I want to have pets with a unique name.
In the POST /pet I will pass "name" parameter so I will check on the controller if this already exists, return an error.
I have an ExceptionDetail on my models, which purpose is to handler different errors.
ExceptionDetail model contains the tittle(str), status(int), detail(str), etc.

Also, swagger validates the fields provide depending if they are required or not.
I was checking https://swagger.io/docs/specification/describing-responses/
the documentation of swagger but it is a minimal example in which they describe the code 200 not even default is there.

I went back and checked the petstore example https://github.com/swagger-api/swagger-codegen/blob/master/samples/server/petstore/flaskConnexion/swagger_server/swagger/swagger.yaml

1. I noticed that there is an APIResponse definition: 1) do I need one on my project in order to handler errors? like 409 or any 3xx 4xx ?
2. Currently I am returning the object generated, in this case a Pet instance. Does that means that I need to create an APIResponse insert he pet instance and return it when a 200 http code?
3. I was reading about this topic on other sites. I end up reading this one https://github.com/swagger-api/swagger-codegen/issues/922
   It suggest using abort, and this one about the abort: http://flask-restplus.readthedocs.io/en/stable/errors.html
   Right now, I do not know if that applies, but I was giving it a try.

First I was generating an instance of the ExceptionDetail with the data i needed. I was returning the exception instance ##Result: The server response code is 200.
Then, I was using the flask abort, and it keeps returning 200.

Finally, I saw on the petstore yalm that there are some response error described like in the PUT /pet
So i went to the controller and found it is not implemented, it is just the stub.

I just want to generated the proper response.code = 3xx or 4xx and include my Exception instance describing the issue. So the server is not going to reply with a 200 all the time.

Swagger-codegen version

2.0

Swagger declaration file content or url

Command line used for generation

Steps to reproduce

Related issues/PRs

Suggest a fix/enhancement

Start with the referenced petstore swagger.yaml and the generated Flask/Connexion controller, then compare documented error responses with the current stub behavior. Clarify how non-200 responses and the ExceptionDetail model should be represented, and document or implement a resolved approach with a reproducible example.