title: gfs.chunks giving undefined for mongodb in express
body: <p>I am trying to data from the .chunks from gridFS. But I am not able to do so. While doing</p>
  <p><code>gfs.chunks.find()</code> it is giving me error like cannot find for undefined, when I did <code>console.log(gfs.chunks)</code> it showed me undefined, where as <code>console.log(gfs.files)</code> was giving the output. Can someone tell me how could I fix this.</p>
  <pre><code>let gfs;
  
  conn.once('open', () =&gt; {
    // Init stream
    gfs = Grid(conn.db, mongoose.mongo);  
    gfs.collection('users');
    
  });
  </code></pre>