content: import React, { Component } from 'react';
  import { connect } from 'react-redux';
  
  class BookDetail extends Component{
      render() {
          if(!this.props.book) {
              return <div> Select a book to get started. </div>;
          }
          
          return (
              <div> 
                  <h3> Details for : </h3>
                  <div> Title: {this.props.book.title} </div>
                  <div> Pages: {this.props.book.pages} </div>
              </div>
          );
      }
  }
  
  function mapStateToProps(state){
      return {
          book: state.activeBook
      }
  }
  
  export default connect(mapStateToProps)(BookDetail);