I have a Class A created by createClass, while after I transform it into a ES6 class, I caught an err: ``` //Original class code var A = React.createClass({ childContextTypes: { name: React.PropTypes.string }, getChildContext: function() { return { name: "Jonas" }; }, render: function() { return <B />; } }); // ES6 class class A extends React.Component { childContextTypes: { name: React.PropTypes.string }, getChildContext () { return { name: "Jonas" }; }, render () { return <B />; } } ``` May be something wrong in the childContextTypes defining method?