// concurrent/ParallelStreamPuzzle.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
import java.util.*;
import java.util.function.*;
import java.util.stream.*;

public class ParallelStreamPuzzle {
 static class IntGenerator
 implements Supplier<Integer> {
 private int current = 0;
 public Integer get() {
 return current++;
 }
 }
 public static void main(String[] args) {
 List<Integer> x =
 Stream.generate(new IntGenerator())
 .limit(10)
 .parallel() // [1]
 .collect(Collectors.toList());
 System.out.println(x);
 }
}
/* Output:
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
*/