title: @Optional annotation not found
body: <p>I'm using com4j to generate Java type definitions from a COM type library. The generated code contains a lot of uses of the @Optional annotation, for example:</p>
  
  <pre><code>@DISPID(14) //= 0xe. The runtime will prefer the VTID if present
  @VTID(23)
  void mail(
      java.lang.String sendTo,
      @Optional @DefaultValue("") java.lang.String sendCc,
      @Optional @DefaultValue("0") int option,
      @Optional @DefaultValue("") java.lang.String subject,
      @Optional @DefaultValue("") java.lang.String comment);
  </code></pre>
  
  <p>However @Optional is not resolving and I'm unable to find where it's defined.</p>