remove foo

Author: mocheng

chapter-02/demo/src/ControlPanel.js

@@ -10,7 +10,7 @@ class ControlPanel extends Component {
   render() {
     return (
       <div style={style}>
-        <Counter caption="First" foo/>
+        <Counter caption="First" />
         <Counter caption="Second" initValue={10} />
         <Counter caption="Third" initValue={20} />
       </div>