Something like the @NonNull annotation? https://blogs.oracle.com/java-platform-group/entry/java_8_s_new_type https://blogs.oracle.com/java-platform-group/entry

Something like the @NonNull annotation? https://blogs.oracle.com/java-platform-group/entry/java_8_s_new_type https://blogs.oracle.com/java-platform-group/entry/java_8_s_... Edit: @NonNull rather than @NotNull. This annotation has existed in various guises and frameworks for a while, usually as @NotNull which is is probably why it's called @NonNull (avoiding breaking changes)