The problem

Consider that other developers will try to read and understand your value class while looking only at your hand-written class, not the actual (generated) implementation class. If you mark your concrete methods final, they won’t have to wonder whether the generated subclass might be overriding them. This is especially helpful if you are underriding equals, hashCode or toString!

Reference: https://github.com/google/auto/blob/master/value/userguide/practices.md#mark-all-concrete-methods-final

NOTE: Since @Memoized methods can’t be final, the check doesn’t flag them.

Suppression

Suppress false positives by adding the suppression annotation @SuppressWarnings("AutoValueFinalMethods") to the enclosing element.