old_contents: import React, { Component } from 'react';
  import ReactDom from 'react-dom';
  import YTSearch from 'youtube-api-search';
  import SearchBar from './components/search_bar';
  import VideoList from './components/video_list';
  import VideoDetail from './components/video_detail';
  // const API_KEY = 'PLACE_YOUR_API_KEY_HERE';
  
  class App extends Component {
  	constructor (props) {
  		super(props);
  
  		this.state = { 
  			videos: [],
  			selectedVideo: null
  		};
  
  		YTSearch({key: API_KEY, term: 'dragonball super'}, (videos) => {
  			console.log(videos);
  			this.setState({ 
  				videos: videos,
  				selectedVideo: videos[0]
  			});
  		});
  	}
  
  	render () {
  		return (	
  			<div>
  				<SearchBar />
  				<VideoDetail video={this.state.selectedVideo} />
  				<VideoList 
  					videos={this.state.videos} 
  					onVideoSelect={selectedVideo => this.setState({selectedVideo})}
  				/>
  			</div>
  		);
  	}
  }
  
  ReactDom.render(<App />, document.querySelector('.container'));
new_contents: import React, { Component } from 'react';
  import ReactDom from 'react-dom';
  import YTSearch from 'youtube-api-search';
  import SearchBar from './components/search_bar';
  import VideoList from './components/video_list';
  import VideoDetail from './components/video_detail';
  import file from './variables.js';
  // const API_KEY = 'PLACE_YOUR_API_KEY_HERE';
  const API_KEY = file.data;
  
  class App extends Component {
  	constructor (props) {
  		super(props);
  
  		this.state = { 
  			videos: [],
  			selectedVideo: null
  		};
  
  		YTSearch({key: API_KEY, term: 'dragonball super'}, (videos) => {
  			console.log(videos);
  			this.setState({ 
  				videos: videos,
  				selectedVideo: videos[0]
  			});
  		});
  	}
  
  	render () {
  		return (	
  			<div>
  				<SearchBar />
  				<VideoDetail video={this.state.selectedVideo} />
  				<VideoList 
  					videos={this.state.videos} 
  					onVideoSelect={selectedVideo => this.setState({selectedVideo})}
  				/>
  			</div>
  		);
  	}
  }
  
  ReactDom.render(<App />, document.querySelector('.container'));
subject: Add import for variables file, set a const API_KEY as the data from variables file.