@Test
    public void testExplicitDistributionBitIncrease() throws ParseException {
        int distBits = 12;

        BucketIdFactory idFactory = new BucketIdFactory();
        ProgressToken p = new ProgressToken();

        VisitorIterator iter = VisitorIterator.createFromDocumentSelection(
                "id.user == 1234 or id.user == 6789 or id.user == 8009", idFactory, distBits, p);

        assertEquals(iter.getDistributionBitCount(), distBits);
        assertEquals(p.getDistributionBitCount(), distBits);
        assertEquals(iter.getBucketSource().getDistributionBitCount(), distBits);

        iter.update(iter.getNext().getSuperbucket(), ProgressToken.FINISHED_BUCKET);
        iter.setDistributionBitCount(16);

        assertEquals(iter.getDistributionBitCount(), 16);
        assertEquals(p.getDistributionBitCount(), 16);
        assertEquals(iter.getBucketSource().getDistributionBitCount(), 16);
        // Changing dist bits for explicit source should change nothing
        assertEquals(p.getPendingBucketCount(), 2);
        assertEquals(p.getFinishedBucketCount(), 1);
        assertEquals(p.getTotalBucketCount(), 3);
    }
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