def METHOD_NAME(self):
    d = Defragmenter()
    d.add_static_size(10, 2)
    d.add_data(10, bytearray(b'\x10'))
    ret = d.get_message()
    self.assertIsNone(ret)
    d.add_data(10, bytearray(b'\x11'))
    ret = d.get_message()
    self.assertIsNotNone(ret)
    msg_type, data = ret
    self.assertEqual(10, msg_type)
    self.assertEqual(bytearray(b'\x10\x11'), data)
    ret = d.get_message()
    self.assertIsNone(ret)