Memoize usage

MemoizeTest.java

import java.util.Random;
import java.util.concurrent.*;
import lombok.Memoize;

public class MemoizeTest {

    @Memoize
    public static int test(final int k){
        System.out.println("test " + k);
        return k+2;
    }
    
    @Memoize
    public static int fib(final int n){
        if (n <= 1) return n;
        return fib(n-1) + fib(n-2);
    }
    
    public static void main(String[] args) throws InterruptedException {
        System.out.println(test(100));
        System.out.println(test(200));
        System.out.println(test(100));
        System.out.println(test(200));
        
        final Random r = new Random();
        
        Runnable run = new Runnable() {
            @Override
            public void run() {
                for (int i=0; i<10000000; i++){
                    int k = r.nextInt(20);
                    assert(test(k) == (k+2));
                }
                System.out.println("Done " + Thread.currentThread().getName());
            }
        };
        
        int nt = 10;
        ExecutorService es = Executors.newFixedThreadPool(nt);
        for (int i=0; i<nt; i++)
            es.execute(run);
        es.shutdown();
        while (!es.isTerminated())
            es.awaitTermination(1000, TimeUnit.MILLISECONDS);
        
        int f = fib(42);
        System.out.println(f);
    }
    
}

/* Output
test 100
102
test 200
202
102
202
test 6
test 12
test 17
test 7
test 9
test 15
test 5
test 13
test 18
test 2
test 1
test 3
test 0
test 10
test 16
test 8
test 19
test 14
test 11
test 4
Done pool-1-thread-1
Done pool-1-thread-8
Done pool-1-thread-9
Done pool-1-thread-2
Done pool-1-thread-10
Done pool-1-thread-6
Done pool-1-thread-4
Done pool-1-thread-5
Done pool-1-thread-7
Done pool-1-thread-3
267914296
*/