k.name }))));
  }
}

const apps = [];

class App extends React.Component {
  constructor(props) {
    super(props);
    apps.push(this);
    this.mountPoint = React.createRef();
    this.state = {
      books: [
        {name: 'Pride and Prejudice' },
        {name: 'To Kill a Mockingbird' },
        {name: 'The Great Gatsby' },
      ],
    };
  }

  render() {
    return e(React.Fragment, null,
      e(AppHeader, {bookCount: this.state.books.length}, null),
      e(NewBook, {onNewBook: bookName => this.on