docs: protected Cache<String, InMemorySession> newSessionCache(SessionConfiguration configuration) {
          Caffeine<String, InMemorySession> builder = Caffeine
              .newBuilder()
              .removalListener(newRemovalListener())
              .expireAfter(newExpiry());
          configuration.getMaxActiveSessions().ifPresent(builder::maximumSize);
          return builder.build();
      }