anchor.diff:            key: flexKey
           )
         ));
  -      Size flexSize = tester.findElementByKey(flexKey).renderObject.size;
  -      expect(flexSize.width, equals(100.0));
  -      expect(flexSize.height, equals(600.0));
  +      RenderBox renderBox = tester.findElementByKey(flexKey).renderObject;
  +      expect(renderBox.size.width, equals(100.0));
  +      expect(renderBox.size.height, equals(600.0));
   
         // Column with justifyContent: FlexJustifyContent.collapse
         tester.pumpWidget(new Center(
  
positive.code: import 'package:flutter/widgets.dart';
  import 'package:test/test.dart';
  
  
negative.code:           key: flexKey
          )
        ));
        RenderBox renderBox = tester.findElementByKey(flexKey).renderObject;
        expect(renderBox.size.width, equals(800.0));
        expect(renderBox.size.height, equals(100.0));
  
        // Row with justifyContent: FlexJustifyContent.collapse
        tester.pumpWidget(new Center(
  