title: GWT: uiBinder-based widget cant be instanced second time
body: <p>I created a widget using GWT uiBinder. It works fine, till the moment when I want to instance it second time. After i call constructor second time it returns only raw description from XML and statements in constructor (<code>rootElement.add( new HTML( "panel1" ), leftId );</code>) are just don't work. It throws no error or warning. </p>
  
  <p>Please help</p>
  
  <p>Java class:</p>
  
  <pre><code>public class DashboardLayout extends Composite {
  
  final String leftId = "boxLeft";
  final String rightId = "boxRight";
  
  interface DashboardLayoutUiBinder extends UiBinder&lt;HTMLPanel, DashboardLayout&gt; {
  }
  
  private static DashboardLayoutUiBinder ourUiBinder = GWT.create( DashboardLayoutUiBinder.class );
  
  @UiField
  HTMLPanel htmlPanel;
  
  public DashboardLayout() {
      HTMLPanel rootElement = ourUiBinder.createAndBindUi( this );
      this.initWidget( rootElement );
  
      rootElement.add( new HTML( "panel1" ), leftId );
      rootElement.add( new HTML( "panel2" ), rightId );
  
  }
     }
  </code></pre>
  
  <p>XML descriprion:</p>
  
  <pre><code>&lt;ui:UiBinder xmlns:ui='urn:ui:com.google.gwt.uibinder'
               xmlns:g='urn:import:com.google.gwt.user.client.ui'
               &gt;
      &lt;g:HTMLPanel ui:field="htmlPanel"&gt;
          &lt;table width="100%" border="0" cellspacing="0" cellpadding="0"&gt;
              &lt;tr&gt;
                  &lt;td width="40%" id="boxLeft" class="boxContextLeft"&gt;
  
                  &lt;/td&gt;
  
                  &lt;td width="60%" id="boxRight" class="boxContextRight"&gt;
  
                  &lt;/td&gt;
              &lt;/tr&gt;
          &lt;/table&gt;
      &lt;/g:HTMLPanel&gt;
  &lt;/ui:UiBinder&gt;
  </code></pre>