title: Removing Try failures in collection using flatMap
body: <p>I have a Map[String, String]</p>
  
  <p>How can I simply this expression using flatMap?</p>
  
  <pre><code> val carNumbers = carMap.keys.map(k =&gt; Try(k.stripPrefix("car_number_").toInt)).toList.filter(_.isSuccess)
  </code></pre>
  
  <p>Note: I want to remove the Failure/Success wrapper and just have a List[Int].</p>