@Test
    public void testRangeDistributionBitIncrease1NoPending() throws ParseException {
        int db = 2;
        BucketIdFactory idFactory = new BucketIdFactory();
        ProgressToken p = new ProgressToken();

        // Test for empty progress token. no splitting involved
        VisitorIterator iter = VisitorIterator.createFromDocumentSelection(
                "id.group != \"yahoo.com\"", idFactory, db, p);

        assertEquals(p.getTotalBucketCount(), 4);
        iter.setDistributionBitCount(db + 1);
        assertEquals(p.getTotalBucketCount(), 8);
        assertEquals(p.getDistributionBitCount(), db + 1);
        assertEquals(iter.getDistributionBitCount(), db + 1);
        assertEquals(iter.getBucketSource().getDistributionBitCount(), db + 1);

        int[] desired = new int[] { 0, 4, 2, 6, 1, 5, 3, 7 };
        for (int i = 0; i < 8; ++i) {
            VisitorIterator.BucketProgress bp = iter.getNext();
            assertEquals(bp.getSuperbucket(), new BucketId(db + 1, desired[i]));
        }
    }
Test increasing the distribution bits for a full bucket space range
source with no finished, active or pending buckets
@throws ParseException upon docsel parse failure (shouldn't happen)
documentapi/src/test/java/com/yahoo/documentapi/VisitorIteratorTestCase.java