title: Why creating an OutlineHandler, and passing this outline handler to the ConverterProperties I get NullPointerException with convertToElements method?
body: <p>I need to use </p>
  
  <ul>
  <li><p><strong>HtmlConvert.converToElements(InputStream,converterProperties)</strong></p></li>
  </ul>
  
  <p>But I'm getting <strong>NullPointerException</strong> when I add <strong>converterProperties.setOutlineHandler(outlineHandler)</strong></p>
  
  <p>Is there any reason for this?? I meant, is this a normal behavior?</p>
  
  <p>Becuase when I use other methods like converToDocument I don't have any issue.</p>