anchor.diff:  
   var helloGreeter = react.registerComponent(() => new _HelloGreeter());
   
  -class _CheckBoxComponent extends react.Component2 {
  +class _CheckBoxComponent extends react.Component {
     getInitialState() => {"checked": false};
   
     change(e) {
  
positive.code: import "package:react/react.dart" as react;
  import "package:react/react_dom.dart" as react_dom;
  
  class _HelloComponent extends react.Component2 {
    void componentWillReceiveProps(nextProps) {
      if (nextProps["name"].length > 20) {
        print("Too long Hello!");
  
negative.code: 
  var clockComponent = react.registerComponent(() => new _ClockComponent());
  
  class _ListComponent extends react.Component {
    Map getInitialState() {
      return {
        "items": new List.from([0, 1, 2, 3])
  