private void TestGroupCount()
{
int hr;
int c;
IAMTimelineObj pGroup;
hr = m_pTimeline.GetGroupCount(out c);
DESError.ThrowExceptionForHR(hr);
Debug.Assert(c == 1, "GetGroupCount");
hr = m_pTimeline.ClearAllGroups();
DESError.ThrowExceptionForHR(hr);
hr = m_pTimeline.GetGroupCount(out c);
DESError.ThrowExceptionForHR(hr);
Debug.Assert(c == 0, "ClearAllGroups");
hr = m_pTimeline.AddGroup((IAMTimelineObj)m_pVideoGroup);
DESError.ThrowExceptionForHR(hr);
hr = m_pTimeline.GetGroup(out pGroup, 0);
DESError.ThrowExceptionForHR(hr);
hr = m_pTimeline.RemGroupFromList((IAMTimelineObj)pGroup);
DESError.ThrowExceptionForHR(hr);
hr = m_pTimeline.GetGroupCount(out c);
DESError.ThrowExceptionForHR(hr);
Debug.Assert(c == 0, "RemGroupFromList");
}