uniqueElements in parallel mode - encounter order

[Georgiy Rakov]

Hello,
*
uniqueElements()* method working in parallel mode does not preserve 
encounter order now. Consider following code. *result *will always 
contain sorted numbers in spite of shuffling, i. e. [0, 1, 2, 3, 4, 5, 
6, 7, 8, 9]. I could suppose this is the used algorithm artifact.

    import java.util.ArrayList;
    import java.util.Arrays;
    import java.util.Collections;

    public class UniqueElementsIssue1 {
         public static void main(String arg[]) {
             ArrayList<Integer> data = new ArrayList<>();
             for (int i = 0; i<10; ++i) {
                 for (int k = 0; k<30; ++k) {
                     data.add(i);
                 }
             }
             Collections.shuffle(data);
             ArrayList<Integer> result = new ArrayList<>();
             Arrays.parallel(data.toArray(new
    Integer[0])).uniqueElements().into(result);
         }
    }


While for sequential mode (Arrays.asStream) the encounter order is 
preserved.

Could you please tell if this is considered as expected behavior and 
will be showed in spec; for instance something like following could be 
there.
/Having been called on stream in sequential mode, UniqueElements 
preserve encounter order.
Having been called on stream in parallel mode, UniqueElements doesn't 
preserve encounter order.
/
The code above is attached for your convenience.

Thanks,
Georgiy.
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