public ClipTimeToViewportTimeRangeColumnGenerator(TGenerator timestampGenerator)
 {
     this.Generator         = timestampGenerator;
     this.ViewPortContainer = new VisibleTableRegionContainer();
 }
 public ClipTimeToViewportTimestampColumnGenerator(TGenerator timestampGenerator)
 {
     this.generator = timestampGenerator;
     this.viewport  = new VisibleTableRegionContainer();
 }