an impure parallel stream that should only map but actually serves as random number generator

ParallelStreamTest.java

import java.util.*;
import java.util.function.*;
import java.util.stream.*;

public class ParallelStreamTest {

   static class IntGenerator implements Supplier<Integer> {

       private int current = 0;

       public Integer get() {
           return current++;
       }
   }

   public static final void main(String[] args) {
       Stream<Integer> s = Stream.generate(new IntGenerator());

       List<Integer> xs = s
           .limit(10)
           .parallel()
           .map(x -> x * 2)
           .collect(Collectors.toList());

       System.out.println(xs);
   }
}
// Kudos: Volker Steiss