title: How to specify a List<MyCustomType> as a "Return Type" for a UML Interface Property
body: <p>In my Visio 2007 UML document I am unable to figure out how I can add an operation to an Interface that returns a generic <code>List&lt;MyCustomType&gt;</code> type.</p>
  
  <p>For example:</p>
  
  <p>Say I have a class named "MyClass" and an Interface named "IFace". IFace has a signature of a method that returns a Generic List of MyClass.</p>
  
  <p>For clarity, here's an example of the C# code:</p>
  
  <pre><code>namespace StackO
  {
      public interface IFace
      {
          List&lt;MyClass&gt; SomeMethod(string data);    
      }
  
      public class MyClass
      {
      }
  }
  </code></pre>
  
  <p>Here's a screenshot of where I'm stuck:
  <img src="https://i.stack.imgur.com/eyWWv.png" alt="enter image description here"> </p>
  
  <p>It seems as though the only way to specify a <code>List&lt;MyClass&gt;</code> as my Return Type is to create another user-defined datatype that is explicitly written as <code>List&lt;MyClass&gt;</code>. If this is the case, so be it. However, I'm posting this in hopes that there is a better/proper way to do this.</p>
  
  <p>How can I define the Return Type of an Operation of a Visio Interface to be a Generic List of a User-Defined Datatype?</p>