title: Why I need that field like that
body: <pre><code>case class AlertWindowDto(id: String)
  
  protected val InitialWindowPeriodOneOnPeak = AlertWindowDto(ValidId)
  
  protected val ValidId = "someSite"
  </code></pre>
  
  <p>I saw these there lines in different different classes. just I put together for understanding. </p>
  
  <p>In general, If i am creating an dummy or some object of Class, then I give some value or null or empty string. What is the need of creating another field ValidId and assign some value and assign that field to final object. </p>
  
  <p>is there any benefit, or anything help in test cases.</p>
  
  <p>could you please help me.</p>