anchor.diff:  
   var checkBoxComponent = react.registerComponent(() => new _CheckBoxComponent());
   
  -class _ClockComponent extends react.Component2 {
  +class _ClockComponent extends react.Component {
     Timer timer;
   
     getInitialState() => {'secondsElapsed': 0};
  
positive.code: 
  var helloComponent = react.registerComponent(() => new _HelloComponent());
  
  class _HelloGreeter extends react.Component2 {
    var myInput;
    getInitialState() => {"name": "World"};
  
  
negative.code: 
  var contextComponent = react.registerComponent(() => new _ContextComponent());
  
  class _ContextConsumerComponent extends react.Component {
    @override
    Iterable<String> get contextKeys => const ['foo'];
  
  