title: How do I return an id string instead of a _bsontype with NestJS Serialization
body: <p>When using</p>
  
  <pre><code>@UseInterceptors(ClassSerializerInterceptor)
  </code></pre>
  
  <p>like it is explained in the Documentation <a href="https://docs.nestjs.com/techniques/serialization" rel="nofollow noreferrer">here</a></p>
  
  <p>I get the desired filtered result, however while using mongodb the id is formatted in <code>_bsontype</code> instead of a normal <code>string</code> like it used to be without the interceptor like this:</p>
  
  <pre><code>{
      "id": {
          "_bsontype": "ObjectID",
          "id": {
              "0": 92,
              "1": 108,
              "2": 182,
              "3": 85,
              "4": 185,
              "5": 20,
              "6": 221,
              "7": 12,
              "8": 56,
              "9": 66,
              "10": 131,
              "11": 172
          }
      },
      "createdAt": "2019-02-20T02:07:17.895Z",
      "updatedAt": "2019-02-20T02:07:17.895Z",
      "firstName": "The First Name",
      "lastName": "The Last Name",
      "email": "giberish@gmail.com"
  }
  </code></pre>
  
  <p>How can I convert it back to a normal id string like this?</p>
  
  <pre><code>{
      "id": "5c6cb655b914dd0c384283ac",
      "createdAt": "2019-02-20T02:07:17.895Z",
      "updatedAt": "2019-02-20T02:07:17.895Z",
      "firstName": "The First Name",
      "lastName": "The Last Name",
      "email": "giberish@gmail.com"
      "password": "okthen"
  }
  </code></pre>