title: insertMany Handle Duplicate Errors
body: <p>I want to bulk insert (array of object) into my document but I want to prevent duplicate records, couldn't find a way to do it with insertMany. </p>
  
  <pre><code>const Song = require('../models/song');
  Song.insertMany([{id:1, name:"something"},{id:2, name:"something else"])
      .then((result) =&gt; {
        res.json({
          result
        })
      })
  </code></pre>
  
  <p>Above code worked but if the record is the same it will still get inserted.</p>