// "Replace with 'peek'" "true" import java.util.concurrent.atomic.AtomicInteger; import java.util.stream.IntStream; public class Main { void test() { AtomicInteger counter = new AtomicInteger(); int[] ints = IntStream.range(0, 100) .filter(x -> x % 3 == 0) .peek((x -> counter.incrementAndGet())) .toArray(); System.out.println(counter.get()); } }