anchor.diff:  import 'dart:ui' as ui;
  +import 'dart:ui';
   
   import 'package:fl_chart/fl_chart.dart';
   import 'package:fl_chart/src/chart/base/axis_chart/axis_chart_data.dart';
  
positive.code: 
          final double rightChartPadding = getExtraNeededHorizontalSpace() - getLeftOffsetDrawSize();
          final Offset to =
          Offset(viewSize.width - rightChartPadding, getPixelY(line.y, chartUsableSize));
  
          extraLinesPaint.color = line.color;
          extraLinesPaint.strokeWidth = line.strokeWidth;
  
          canvas.drawDashedLine(from, to, extraLinesPaint, line.dashArray);
        }
      }
  
  
negative.code: 
          final double bottomChartPadding = getExtraNeededVerticalSpace() - getTopOffsetDrawSize();
          final Offset to =
              Offset(getPixelX(line.x, chartUsableSize), viewSize.height - bottomChartPadding);
  
          extraLinesPaint.color = line.color;
          extraLinesPaint.strokeWidth = line.strokeWidth;
  
          canvas.drawDashedLine(from, to, extraLinesPaint, line.dashArray);
  
          if (line.label != null) {
            final VerticalLineLabel label = line.label;
            final TextStyle style = TextStyle(fontSize: 11, color: line.color).merge(label.style);
            final EdgeInsets padding = label.padding ?? EdgeInsets.zero;
  
            final TextSpan span = TextSpan(
              text: label.labelResolver(line),
              style: style,
            );
  
            final TextPainter tp = TextPainter(
              text: span,
              textDirection: TextDirection.ltr,
            );
  
            tp.layout();
  
            tp.paint(
              canvas,
              label.alignment.withinRect(
                Rect.fromLTRB(
                  to.dx - padding.right - tp.width,
                  from.dy + padding.top - topChartPadding,
                  from.dx + padding.left,
                  to.dy - padding.bottom + bottomChartPadding,
                ),
              ),
            );
          }
        }
      }
    }
  