title: Spring data mongodb remove a property from a document using MongoTemplate
body: <p>I have a document as shown below</p>
  
  <pre><code>{
      "_id" : ObjectId("5864ddd8e38112fd70b89893"),
      "_class" : "com.apic.models.UserReg",
      "name" : "xxx",
      "email" : "xxx.xxx@xxx.com"
      "activationToken" : "fe8376ea2dbdf61ebc"
  }
  </code></pre>
  
  <p>How can I remove the property <code>activationToken</code> from it using Spring <code>MongoTemplate</code>?</p>