There is no way to indicate the requestBody is required

[Kieun]

With current implementation, in case where there is request body for the API, the generated spec always presents that the request body is optional (which is not marked with required).

AS-IS

paths:
  /v1/authentication/request:
    post:
      requestBody:

....

TO-BE (if the request body is required)

paths:
  /v1/authentication/request:
    post:
      requestBody:
         required: true
....

It seems that there is no way to mark required for RequestFieldsSnippet, such as optional() or required() method. Instead, we might leverage attributes, Map<String, Object> to indicate that the requestBody is required.

Is this reasonable?