### Question:
LongSortedArraySet extends AbstractLongSortedSet implements Serializable { @Override public LongSortedSet subSet(long startKey, long endKey) { int start = keys.findLowerBound(startKey); int end = keys.findLowerBound(endKey); return new LongSortedArraySet(keys.subIndex(start, end)); } LongSortedArraySet(@Nonnull SortedKeyIndex ks);  LongSortedArraySet(@Nonnull Collection<Long> items);  LongSortedArraySet(long[] items); SortedKeyIndex getIndex(); @Deprecated SortedKeyIndex getDomain(); @Override LongComparator comparator(); @Override long firstLong(); @Override long lastLong(); @Override LongBidirectionalIterator iterator(); @Override LongBidirectionalIterator iterator(long key); @Override LongSortedSet subSet(long startKey, long endKey); @Override LongSortedSet headSet(long key); @Override LongSortedSet tailSet(long key); @Override int size(); @Override boolean contains(long key); LongSortedSet randomSubset(Random rng, int n, LongSet... exclude);  }### Answer:
@Test public void testSubSet() { long[] data = {0, 42, 5, 2, 6, 1, 7}; LongSortedSet set = new LongSortedArraySet(data); assertEquals(data.length, set.size()); testSetSimple(set.subSet(2, 7)); }