content: import React from 'react';
  import PropTypes from 'prop-types';
  import Navigation from './Navigation';
  
  // This is a class-based component because the current
  // version of hot reloading won't hot reload a stateless
  // component at the top-level.
  class App extends React.Component {
      render() {
          return (
              <div className="wrapper">
                  <Navigation />
                  <div className="container-fluid">
                        {this.props.children}
                  </div>
              </div>
          );
      }
  }
  
  App.propTypes = {
      children: PropTypes.element
  };
  
  export default App;
  