title: Validating Empty Json using wix/accord
body: <p>How can I validate empty json using wix/accord</p>
  
  <p>I have done research and found <a href="https://github.com/wix/accord/issues/58" rel="nofollow noreferrer">https://github.com/wix/accord/issues/58</a>.</p>
  
  <p>But, It is not the case I want.</p>
  
  <p>For example: 
   I have a class</p>
  
  <pre><code>  case class Test(name:Option[String], subject:Option[String])
  </code></pre>
  
  <p>I have my validator</p>
  
  <pre><code>object TestValidator{
  val validateTest = validator[Test] { p =&gt;
  p.name must notEmpty
  }
  </code></pre>
  
  <p>It works when name is not provided. </p>
  
  <p>But if I send empty json as </p>
  
  <pre><code>{ }
  </code></pre>
  
  <p>It response with None.get error</p>