require(['react', 'react-dom'], function(React, ReactDOM) {
  var CSSTransitionGroup = React.addons.CSSTransitionGroup;
  ReactDOM.render(
    React.createElement(CSSTransitionGroup, {
      transitionName: 'example',
      transitionAppear: true,
      transitionAppearTimeout: 500,
      transitionEnterTimeout: 0,
      transitionLeaveTimeout: 0,
    }, React.createElement('h1', null,
      'Hello World!'
    )),
    document.getElementById('container')
  );
});