text: import React from 'react';
  import logo from './logo.svg';
  import './App.css';
  import {extendObservable} from 'mobx'
  import {observer} from 'mobx-react'
  
  class App extends React.Component {
  	
  	constructor(props) {
  		super(props);
  		
  		extendObservable(this,{
  			counter:0
  		})
  	}
  	
  	onIncrement = () => {
  		this.counter++
  	}
  	
  	onDecrement = () => {
  		this.counter--
  	}
  	
  	render() {
  	  return (
  		<div className="App">
  			Counter:{this.counter}
  			<button onClick={this.onIncrement}>Increment</button>
  			<button onClick={this.onDecrement}>Decrement</button>
  		</div>
  	  );
  	}
  }
  
  export default observer(App);
  