/// ------------------------------------------------------------------------------------
 public void AddIgnoredSegment(TimeSpan newBoundary)
 {
     Tiers.AddIgnoredSegment((float)newBoundary.TotalSeconds);
     _undoStack.Push(new SegmentChange(TimeTier.Segments.First(s => s.TimeRange.End == newBoundary).TimeRange.Copy(),
                                       c => { Tiers.GetTranscriptionTier().Segments.Last().Text = string.Empty; RevertNewSegment(c); }));
     OnSegmentBoundaryChanged();
 }