text: import React from 'react';
  import Redlight from './Redlight';
  import Yellowlight from './Yellowlight';
  import Greenlight from './Greenlight';
  
  export default class TrafficLight extends React.Component {
  
  	constructor(props) {
  		super(props);
  		this.state = {
  			color:"red",
  			timer:0
  		}
  	}
  	
  	componentDidMount() {
  		// TODO: start the timer and change the timer state to save the handle to the timer. Use setInterval-function.
  	}
  	
  	changeLight = () => {
  		// TODO: Change the state color variable of the application from red->green->yellow->red 
  	}
  	
  	render() {
  		let style = {
  			backgroundColor:"black",
  			height:630,
  			width:220,
  			margin:"auto",
  			marginTop:100,
  			paddingTop:10
  		}
  		return(
  			<div style={style}>
  				<Redlight color={this.state.color}/>
  				<Yellowlight color={this.state.color}/>
  				<Greenlight color={this.state.color}/>
  			</div>
  		)
  	}
  	
  }
  
  