### Question:
PrimitiveLongCollections { public static long[] deduplicate(long[] values) { int unique = 0; for (int i = 0; i < values.length; i++) { long value = values[i]; for (int j = 0; j < unique; j++) { if (value == values[j]) { value = -1; break; } } if (value != -1) { values[unique++] = values[i]; } } return unique < values.length ? Arrays.copyOf(values, unique) : values; } private  PrimitiveLongCollections(); static PrimitiveLongIterator iterator(final long... items); static PrimitiveLongIterator concat(PrimitiveLongIterator... primitiveLongIterators); static PrimitiveLongIterator concat(Iterable<PrimitiveLongIterator> primitiveLongIterators); static PrimitiveLongIterator filter(PrimitiveLongIterator source, final LongPredicate filter); static PrimitiveLongResourceIterator filter(
        PrimitiveLongResourceIterator source,
        final LongPredicate filter
    ); static PrimitiveLongIterator range(long start, long end); static long single(PrimitiveLongIterator iterator, long defaultItem); static int indexOf(PrimitiveLongIterator iterator, long item); static int count(PrimitiveLongIterator iterator); static long[] asArray(PrimitiveLongIterator iterator); static long[] asArray(Iterator<Long> iterator); static PrimitiveLongIterator emptyIterator(); static PrimitiveLongIterator toPrimitiveIterator(final Iterator<Long> iterator); static Iterator<T> map(final LongFunction<T> mapFunction, final PrimitiveLongIterator source); static List<Long> asList(PrimitiveLongIterator iterator); static Iterator<Long> toIterator(final PrimitiveLongIterator primIterator); static PrimitiveLongResourceIterator resourceIterator(
        final PrimitiveLongIterator iterator,
        final Resource resource
    ); static Set<Long> toSet(PrimitiveLongSet set); static Set<Long> toSet(PrimitiveLongIterator iterator); static long[] deduplicate(long[] values); static final long[] EMPTY_LONG_ARRAY; }### Answer:
@Test void shouldDeduplicate() { long[] array = new long[]{1L, 1L, 2L, 5L, 6L, 6L}; long[] deduped = PrimitiveLongCollections.deduplicate(array); Assertions.assertArrayEquals(new long[]{1L, 2L, 5L, 6L}, deduped); }