title: issue in understandind `WebSocketServer` is not a class
body: <p>i am implementing the websockets and installed the ws package also in my project but when i initialising the <code>const WSS= new WebSocketServer({port: 3232})</code> the typeError is shown <code>WebSocketServer is not a constructor</code>.</p>
  
  <pre><code>const WebSocketServer = require('ws').server;
  const WSS = new WebSocketServer({port: 3232});
  
  WSS.on('connection',(ws)=&gt;{
    console.log('we are connected');
  });
  </code></pre>
  
  <p>typeError is shown <code>webSocketServer is not a constructor</code></p>