/// ------------------------------------------------------------------------------------
 /// <summary>
 /// If the time tier contains more segments than all the other text tiers, this method
 /// will add a number of segments to each text tier so each tier contains the same
 /// number of segments. Added text segments are filled with an empty string.
 /// </summary>
 /// ------------------------------------------------------------------------------------
 public void CreateMissingTextSegmentsToMatchTimeSegmentCount()
 {
     foreach (var textTier in Tiers.OfType <TextTier>()
              .Where(t => t.Segments.Count < TimeTier.Segments.Count))
     {
         while (textTier.Segments.Count < TimeTier.Segments.Count)
         {
             textTier.AddSegment(string.Empty);
         }
     }
 }