anchor.diff:      this.bar,
       this.barIndex,
       FlSpot spot,
  -  )   : spotIndex = bar.spots.indexOf(spot),
  -        super(spot.x, spot.y);
  +    )   : spotIndex = bar.spots.indexOf(spot),
  +      super(spot.x, spot.y);
   }
   
   /// Holds data of showing each row item in the tooltip popup.
   class LineTooltipItem {
  +
     /// Showing text.
     final String text;
   
  
positive.code:   /// Lerps a [LineChartData] based on [t] value, check [Tween.lerp].
    @override
    LineChartData lerp(double t) => begin.lerp(begin, end, t);
  }
  
negative.code: /// [indicatorBelowLine] we draw a vertical line below of the touched spot
  /// [touchedSpotDotData] we draw a larger dot on the touched spot to bold it
  class TouchedSpotIndicatorData {
  
    /// Determines line's style.
    final FlLine indicatorBelowLine;
  
  