title: case class to json (partial) conversion
body: <p>I have following case class:</p>
  
  <pre><code>case class Test(name: String, email: String, phone: String)
  </code></pre>
  
  <p>So in order to be able to serialize to JSON I wrote:</p>
  
  <pre><code>implicit val testWrites: Writes[Test] = (
    (__ \ "name").write[String] and
      (__ \ "email").write[String] and
      (__ \ "phone").write[String]
    )(unlift(Test.unapply))
  </code></pre>
  
  <p>I want to use this as something like DTO object, so I can exclude some fields while serizalizing.
  Let's we say I want to show only <code>name</code> and <code>email</code> fields.</p>
  
  <p>I tried something like this:</p>
  
  <pre><code>implicit val testWrites: Writes[Test] = (
    (__ \ "name").write[String] and
      (__ \ "email").write[String]
    )(unlift(Test.unapply))
  </code></pre>
  
  <p>But this is giving me compile error -> <code>Application does not take parameters</code>.</p>
  
  <p>Does anyone know what is the problem, and how I can achieve mentioned idea?</p>