title: Dictionary<string,List<service>> not allowed in staruml
body: <p>I am using whitestaruml 5.4
  with class diagram, i can't seem to be able to type this attribute</p>
  
  <pre><code>ServiceCategory: Dictionary&lt;string,List&lt;service&gt;&gt;
  </code></pre>
  
  <p>But <code>Dictionary&lt;string,List&lt;service&gt;&gt;</code> is a valid type for C#, how to get over this?</p>