Find a good way to work with optional fields

[haraldmeyer]

As most / all fields are optional the the JSON schema of the OpenAPI specification they are all marked as optional. This makes it difficult to work with the fields.

Challenge is that some fields are known to always be present in responses from C8Y (like ID in most objects and the severity in alarms) but some other fields MUST be empty on POST requests (like ID).

Maybe there is a good way of supporting both cases?