A common annotation to declare that annotated elements cannot be null. Leverages JSR 305 meta-annotations to indicate nullability in Java to common tools with JSR 305 support and used by Kotlin to infer nullability of the API.

Should be used at parameter, return value, and field level. Method overrides should repeat parent @NonNull annotations unless they behave differently.

Use @NonNullApi (scope = parameters + return values) and/or @NonNullFields (scope = fields) to set the default behavior to non-nullable in order to avoid annotating your whole codebase with @NonNull.