static AccessPredicate permitAll() {
        return AccessPredicates.PERMIT_ALL;
    }
Special constant that symbolizes that everybody (including unauthenticated users) can access the instance (no
protection).

<p>
<b>Note:</b> This is a special constant, that does not allow execution and mutation. It's sole purpose is to
avoid ambiguity for {@code null} values. It should only be used in {@code ==} comparisons.
</p>

@return A special constant that symbolizes public access.
grpc-server-spring-boot-starter/src/main/java/net/devh/boot/grpc/server/security/check/AccessPredicate.java