title: react MapboxGeocoder is not defined no-undef
body: <p>Everything was alright but suddenly I got this error. I have googled many times but no solution. Can anybody help me out, please?
  <a href="https://i.stack.imgur.com/C2FI5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/C2FI5.png" alt="enter image description here"></a></p>
  
  <p>Code I have used</p>
  
  <pre><code>import React, { Component } from 'react';
  import MapboxGl from 'mapbox-gl/dist/mapbox-gl';
  import '../App.css';
  
  class MapContent extends Component {
  
      componentDidMount() {
          MapboxGl.accessToken = ACCESS_TOKEN;
  
          var map = new MapboxGl.Map({
              container: this.Mapcontainer,
              style: 'mapbox://styles/mapbox/streets-v9',
              center: [-74.50, 40], // starting position
              zoom: 9 // starting zoom
          });
  
          var geocoder = new MapboxGeocoder({
              accessToken: MapboxGl.accessToken
          });
  
          map.addControl(geocoder);
      }
  
      render() {
          return (
              &lt;div className='MapContent' ref={(x) =&gt; { this.Mapcontainer = x }}&gt;
              &lt;/div&gt;
          )
      }
  }
  
  export default MapContent;
  </code></pre>