docs: @SuppressWarnings("unchecked")
     public static <B> Class<? extends Builder<B>> builderFor(B built) throws CacheConfigurationException {
        BuiltBy builtBy = built.getClass().getAnnotation(BuiltBy.class);
        if (builtBy == null) {
           throw new CacheConfigurationException("Missing BuiltBy annotation for configuration bean " + built.getClass().getName());
        }
        return (Class<? extends Builder<B>>) builtBy.value();
     }