protected void ReportSeekCompleted (long timeSeekedTo)
{
// FIXME: wrong/overzealous validations wrt SL2 (see unit tests)
if (closed || media_element == null || demuxer == IntPtr.Zero)
throw new InvalidOperationException ();
NativeMethods.imedia_demuxer_report_seek_completed (demuxer, (ulong) timeSeekedTo);
}