This package provides class, field, and method level annotations for
describing thread-safety policies. These annotations are relatively
unintrusive and are beneficial to both users and maintainers. Users can see
immediately whether a class is thread-safe, and maintainers can see
immediately whether thread-safety guarantees must be preserved. Annotations
are also useful to a third constituency: tools. Static code-analysis tools
may be able to verify that the code complies with the contract indicated by
the annotation, such as verifying that a class annotated with @Immutable
actually is immutable.