title: How to get max min item from a list in Drools
body: <p>I have a class</p>
  
  <pre><code>class Person {
      public Date dateOfBirth;
      public List&lt;Person&gt; children;
  }
  </code></pre>
  
  <p>I would like to create a Drools rule that gets me the oldest child. For example:</p>
  
  <pre><code>rule "Oldest Child"
      when
          $person: Person()
          $oldestChild: Person() from $person.children
      then
          insert($oldestChild)
  end
  </code></pre>
  
  <p>As written, $oldestChild is a list but I'd really like to be an actual oldest child (single object instead of a list). I played around with accumulate a bit but couldn't get it to work. Any ideas?</p>