'Test the sequence generator without rollover'

def test_sequence_generator_no_rollover(self):

    from boto.sdb.db.sequence import SequenceGenerator
    gen = SequenceGenerator('ABC')
    assert (gen('') == 'A')
    assert (gen('A') == 'B')
    assert (gen('B') == 'C')
    assert (gen('C') == 'AA')
    assert (gen('AC') == 'BA')
