Foreign Keys must be nullable?

[2x2xplz]

DBFlow Version: upgrading from 4.0.beta-7 to 4.0.5
Issue Kind (Bug, Question, Feature): Question

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Description:
When upgrading to the latest DBFlow version, all my Foreign Keys are rejected in the build process because they are not nullable types (using Kotlin). While I understand that in theory an FK may have reason to be null, it can also be viewed as a violation of referential integrity (especially if the FK references a Primary Key).

Is it possible to turn this off? Otherwise the entire app must be re-written to support null checking on all of these objects, even though they should never be null.

I did see #1344 where you state "Currently foreign key fields don't support NOT NULL on individual references." Can they support NOT NULL on the entire database or codebase, if not individually?

[2x2xplz]

updated after 4.1.0 release in #1459 . Closed here