title: How to set rowspan and colspan values on gwt Grid cell containing a widget?
body: <p>let's say I have a code like this</p>
  
  <pre><code>Grid g = new Grid(2,2);
  Label l = new Label("Hello");
  g.setWidget(0,1, l);
  s.setColspan(0,1,2); // there is no such method :(
  </code></pre>
  
  <p>So how can I set rowspan and colspan values on gwt Grid cell containing a widget?</p>