code: public void encodeChildren(FacesContext context, UIComponent component)
          throws IOException {
          if (context == null || component == null) {
              throw new NullPointerException();
          }
          if (component.getChildCount() > 0) {
          	Iterator<UIComponent> kids = component.getChildren().iterator();
          	while (kids.hasNext()) {
          	    UIComponent kid = kids.next();
          	    kid.encodeAll(context);
          	}
          }
      }
docs: <p>Render the child components of this {@link UIComponent}, following
  the rules described for <code>encodeBegin()</code> to acquire the
  appropriate value to be rendered.  This method will only be called
  if the <code>rendersChildren</code> property of this component
  is <code>true</code>.</p>
  
  @param context {@link FacesContext} for the response we are creating
  @param component {@link UIComponent} whose children are to be rendered
  
  @throws IOException if an input/output error occurs while rendering
  @throws NullPointerException if <code>context</code>
  or <code>component</code> is <code>null</code>