Is it possible to identify for every field if it can be nullable or not in Adobe Analytics?

In the Api Documentation of the Adobe Analytics, we could not find details regarding whether or not fields supported by Adobe endpoints can have null values.

Is there any way through which we can find whether the fields can be nullable or not?

API documentation link: https://developer.adobe.com/analytics-apis/docs/2.0/apis/

Is there any other approach through which we could find it would be helpful.