const App = React.createClass({
  render() {
    return (
      <div>
        <toolbar>
          <h1>{myTitleAccordingToPage}</h1>
        </toolbar>
        <main>
          {this.props.children}
        </main>
      </div>
    )
  }
})

const A = React.createClass({
  render() {
    return (
      <div>
        Content for A page
      </div>
    )
  }
})

const B = React.createClass({
  render() {
    return (
      <div>
        Content for B page
      </div>
    )
  }
})