Bug: Null annotations are sloppily applied

[mOctave]

• I have searched the existing issues for my problem

Describe the bug
Currently, the null annotations on this project kind of suck and have a lot of issues. These issues should be resolved.

To Reproduce
N/A

Expected behaviour
No nullity warnings when checking this project. Potentially also some intentional null checks even when types aren't supposed to be null.

Screenshots
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Operating system:
N/A

Version:
N/A

Source:
Built from scratch

Additional context
N/A