anchor.diff:  
     @override
     Widget build(BuildContext context) {
  -    return Center(
  -      alignment: Alignment.center,
  -      child: Column(
  -        mainAxisAlignment: MainAxisAlignment.center,
  -        children: <Widget>[
  -          if (errorMsg != null) Text(errorMsg),
  -          RaisedButton(
  -            color: Colors.redAccent,
  -            child: const Text('Try again'),
  -            onPressed: () async {
  -              await handler.fetchAndDispatch();
  -            },
  -          ),
  -        ],
  -      ),
  +    return Column(
  +      mainAxisAlignment: MainAxisAlignment.center,
  +      children: <Widget>[
  +        if (errorMsg != null) Text(errorMsg),
  +        RaisedButton(
  +          color: Colors.redAccent,
  +          child: const Text('Try again'),
  +          onPressed: () async {
  +            await Provider.of<_PlanetHandler>(context, listen: false)
  +                .fetchAndDispatch();
  +          },
  +        ),
  +      ],
       );
     }
   }
  
positive.code:         /// Create planet handler and load the first page.
          /// The first page will only be loaded once, after the handler was created
          return _PlanetHandler(store, api)..fetchAndDispatch();
          return handler;
        },
        [store, api],
      );
  
negative.code:       child: next ? const Text('Next Page') : const Text('Prev Page'),
        onPressed: () async {
          final url = next ? state.planetPage.next : state.planetPage.previous;
          await Provider.of<_PlanetHandler>(context, listen: false)
              .fetchAndDispatch(url);
        },
      );
    }
  