2 PASS Test sequence AppendMode appendBuffer(first media segment)
3 PASS Test sequence AppendMode appendBuffer(second media segment)
4 PASS Test sequence AppendMode appendBuffer(second media segment, then first media segment)
5 PASS Test sequence AppendMode appendBuffer back-to-back(first media segment, then second media segment)
6 PASS Test sequence AppendMode appendBuffer after setting TSO > 0
7 PASS Test sequence AppendMode appendBuffer with large gap between segments.
8 PASS Test sequence AppendMode appendBuffer fully before the appendwindow.
9 PASS Test sequence AppendMode appendBuffer fully after the appendwindow.