anchor.diff:    final IconData icon;
     final String information;
     Widget child;
  -  dynamic onClick;
  +  VoidCallback onClick;
   
     Color get labelColor => colors.shade500;
   
  
positive.code:       label: 'Friends',
        icon: Icons.add,
        information: "You can view your friends' information or "
            "add new friends in this page.",
      );
      _kata = new _Page(
        label: 'Kata',
        icon: Icons.add_box,
        information: "You can view or add katas here, and preview them.\n"
            "submitting is not supported ATM",
      );
      _me = new _Page(
        label: 'Me',
        icon: Icons.edit,
        information: "Information about yourself on Code Wars.\n"
            "You can change your username.",
      );
      _allPages = <_Page>[_friends, _kata, _me];
      _me.onClick = () {
        var dialog = new SimpleDialog(
          contentPadding: new EdgeInsets.all(20.0),
          children: [
            new TextField(controller: _usernameEditingController),
            new FlatButton(onPressed: () {
              Navigator.pop(context);
              showDialog(context: context, child: new RefreshProgressDialog(
                  CodeWarsColors.black.shade100, width: 100, height: 100));
              get(CodeWarsAPI.getUser(_usernameEditingController.text))
                  .then((val) {
                setState(() {
                  var json = new JsonDecoder(null).convert(val.body);
                  _user.username = json['username'];
                  _user.name = json['name'];
                  _user.honor = json['honor'];
                  _user.leaderboardPosition = json['leaderboardPosition'];
                  _user.skills = json['skills'];
                });
                Navigator.pop(context);
              });
            }, child: new Text("OK")),
          ], title: new Text("Reset your username"),
        );
        showDialog(context: context, child: dialog);
      };
      _tabController = new TabController(vsync: this, length: _allPages.length);
      _tabController.addListener(_handleTabSelection);
      _selectedPage = _me;
  
negative.code:               border: new Border(top: new BorderSide(color: Theme
                    .of(context)
                    .dividerColor
                ))),
            child: new Padding(
                padding: const EdgeInsets.all(32.0),
                child: new Text(_selectedPage.information, style: Theme
                    .of(context)
                    .textTheme
                    .subhead)));
      });
    }
  
  