private void TestCountOfType()
{
int hr;
int c, c1;
IAMTimelineObj pTrack1Obj;
hr = m_pTimeline.AddGroup((IAMTimelineObj)m_pVideoGroup);
DESError.ThrowExceptionForHR(hr);
hr = m_pTimeline.CreateEmptyNode(out pTrack1Obj, TimelineMajorType.Track);
DESError.ThrowExceptionForHR(hr);
// tell the composition about the track
IAMTimelineComp pRootComp = (IAMTimelineComp)m_pVideoGroup;
hr = pRootComp.VTrackInsBefore(pTrack1Obj, -1);
DESError.ThrowExceptionForHR(hr);
hr = m_pTimeline.GetCountOfType(0, out c, out c1, TimelineMajorType.Track);
DESError.ThrowExceptionForHR(hr);
Debug.Assert(c == 1 && c1 == 2, "GetCountOfType");
}