title: Dozer: map single field to Set
body: <p>How do you map a single field into a <code>Set</code> in Dozer?</p>
  
  <p>I have a class like:</p>
  
  <pre><code>class FooDTO {
      private IdDto bar;
      private IdDto baz;
  }
  
  class FooDomainObject {
      private List&lt;Id&gt; ids;
  }
  </code></pre>
  
  <p>I'd like to map <code>bar</code> and <code>baz</code> into the <code>ids</code> list, but I can't get it to do this.</p>