title: What is the purpose of Spock's @Unroll annotation
body: <p>I'm having difficulties in understanding the <code>@Unroll</code> annotation of Spock's testing framework. In the docs, it is mentioned</p>
  
  <blockquote>
    <p>Indicates that iterations of a data-driven feature should be made visible
     as separate features to the outside world (IDEs, reports, etc.)</p>
  </blockquote>
  
  <p>Still makes not much sense to me. Could someone explain in layman's terms?</p>