title: How to fix the Product Type Inferred error from Scala's WartRemover tool
body: <p>I'm using <a href="https://github.com/puffnfresh/wartremover">WartRemover</a> tool to avoid possible errors in my Scala 2.11 code.</p>
  
  <p>Specifically, I want to know how to fix the <strong>"<em>Product Type Inferred</em>"</strong> error. </p>
  
  <p>Looking at the repo documentation, I can only see the failure example, but I would like to know how I'm suppose to fix that error:</p>
  
  <p><a href="https://github.com/puffnfresh/wartremover#product">https://github.com/puffnfresh/wartremover#product</a>.</p>
  
  <p>Doing my homework, I end up with this other link that explains how to fix <em>Type Inference Failures</em> errors <a href="https://blog.cppcabrera.com/posts/scala-wart-remover.html">https://blog.cppcabrera.com/posts/scala-wart-remover.html</a>. And I quote "<em>If you see any of the warnings below, the fix is usually as simple as providing type annotations</em>" but I don't understand what that means. I really need a concrete example.</p>