anchor.diff:          ..lineTo(10, 0)
           ..lineTo(10, 10);
   
  +      List<Map<String, dynamic>> results = [];
  +      when(_mockCanvasWrapper.drawDashedLine(
  +              captureAny, captureAny, captureAny, any))
  +          .thenAnswer((inv) {
  +        results.add({
  +          'from': inv.positionalArguments[0] as Offset,
  +          'to': inv.positionalArguments[1] as Offset,
  +          'paint_color': (inv.positionalArguments[2] as Paint).color,
  +          'paint_stroke_width':
  +              (inv.positionalArguments[2] as Paint).strokeWidth,
  +        });
  +      });
  +
         lineChartPainter.drawAboveBar(_mockCanvasWrapper, aboveBarPath,
             filledBelowBarPath, holder, lineChartBarData);
   
  
positive.code: 
        verify(_mockCanvasWrapper.restore()).called(1);
  
        final result3 =
            verify(_mockCanvasWrapper.drawDashedLine(any, any, captureAny, any));
        result3.called(2);
  
        /// Todo, we can only test last painter due to a bug in mockito.
        /// see more details here: https://github.com/dart-lang/mockito/issues/494
        for (Paint item in result3.captured) {
          expect(item.color.alpha, 0);
          expect(item.strokeWidth, 18);
        }
      });
    });
  
negative.code:         ..lineTo(10, 0)
          ..lineTo(10, 10);
  
        List<Map<String, dynamic>> results = [];
        when(_mockCanvasWrapper.drawDashedLine(
                captureAny, captureAny, captureAny, any))
            .thenAnswer((inv) {
          results.add({
            'from': inv.positionalArguments[0] as Offset,
            'to': inv.positionalArguments[1] as Offset,
            'paint_color': (inv.positionalArguments[2] as Paint).color,
            'paint_stroke_width':
                (inv.positionalArguments[2] as Paint).strokeWidth,
          });
        });
  
        lineChartPainter.drawBelowBar(_mockCanvasWrapper, belowBarPath,
            filletAboveBarPath, holder, lineChartBarData);
  
  