'Creating a L{MessageSet} with both a start and end message
number adds the sequence between to the L{MessageSet}; its
serialized form consists that range, its length is the length
of the sequence, and it yields the message numbers inclusively
between the start and end.'

def test_createWithSequence(self):

    m = MessageSet(1, 10)
    self.assertEqual(str(m), '1:10')
    self.assertEqual(len(m), 10)
    self.assertEqual(list(m), [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
