ByteVectorIterator it = a.columnIterator(1, 0, 3);
assertTrue("hasNext 0", it.hasNext());
it.next();
assertEquals("get 0", 0, it.get());
assertEquals("index 0", 0, it.index());
assertTrue("hasNext 1", it.hasNext());
it.next();
assertEquals("get 1", 1, it.get());
assertEquals("index 1", 1, it.index());