title: How to rename path in response for populate
body: <p>I have a query like this:</p>
  
  <pre><code>galleryModel.find({_id: galleryId})
              .populate({
                  model: 'User',
                  path: 'objectId',
                  select: 'firstName lastName'
              })
  </code></pre>
  
  <p>End response for <code>objectId</code> will be like this:</p>
  
  <pre><code>objectId: {
  ...
  }
  </code></pre>
  
  <p>How can I change it to <code>user</code> in response without changing real path?</p>