List<AcknowledgementRange> ranges = seq.getAcknowledgment().getAcknowledgementRange();
assertEquals(0, ranges.size());
seq.acknowledge(message1);
assertEquals(1, ranges.size());
AcknowledgementRange r1 = ranges.get(0);
assertEquals(1, r1.getLower().intValue());
assertEquals(1, r1.getUpper().intValue());
seq.acknowledge(message2);
assertEquals(1, ranges.size());
r1 = ranges.get(0);
assertEquals(1, r1.getLower().intValue());
assertEquals(2, r1.getUpper().intValue());
control.verify();
}