title: Why doesn't HTMLPanel allow add(Widget)?
body: <p>HTMLPanel inherits the <code>add(Widget)</code> method from <code>com.google.gwt.user.client.ui.Panel</code>, but doesn't override it. This leads to an UnsupportedOperationException when called.</p>
  
  <p>Would there be any problems if it was overriding it like FlowPanel does?</p>
  
  <pre><code>@Override
  public void add(Widget w) {
    add(w, getElement());
  }
  </code></pre>
  
  <hr>
  
  <p>Background: HTMLPanel can be constructed faster than FlowPanel (innerHTML vs DOM manipulation). But after construction, it doesn't currently allow to add elements dynamically<sup>*</sup>.</p>
  
  <p><sup>* except for the not so useful method <code>add(Widget widget, String id)</code> , which makes it impossible to use the HTMLPanel twice in a document.</sup></p>