code: public final <U> void addPartial(HtmlView<U> partial, U model) {
          getVisitor().closeBeginTag();
          partial.getVisitor().depth = getVisitor().depth;
          if (this.getVisitor().isWriting())
              getVisitor().write(partial.render(model));
      }
docs: Adds a partial view to this view.
  
  @param partial inner view.
  @param model the domain object bound to the partial view.
  @param <U> the type of the domain model of the partial view.