title: Mongoose overwrite the document rather that `$set` fields
body: <p>Say, i have a document:</p>
  
  <pre><code>{
    _id: 'some_mongodb_id',
    name: 'john doe',
    phone: '+12345678901',
  }
  </code></pre>
  
  <p>I want to update this document:</p>
  
  <pre><code>.findOneAndUpdate({_id: 'some_mongodb_id'}, {name: 'Dan smith'})
  </code></pre>
  
  <p>And the result should be this:</p>
  
  <pre><code>{
    _id: 'some_mongodb_id',
    name: 'Dan smith',
  }
  </code></pre>
  
  <p>The property, that is not specified, should be removed.</p>
  
  <p>How do i do that?</p>