Override 403 response and make it 400 instead. Is this possible?

Is there a reason you can't add the `400` status code directly? 

400: # <----- 400 status
  description: An error occurred.
  content:
    application/json:
      schema:
        type: object
        properties:
          code:
            type: integer
            default: 400
          message:
            type: string
            default: An error occurred.

Or perhaps you could expand on what use case you have? For example where do you see the `403` when you want `400`?