code: @SuppressWarnings("unchecked")
      public V getView() {
          V result = null;
          if (viewName != null) {
              result = (V) viewProvider.getView(viewName);
          }
          return result;
      }
docs: Hands back the View that this Presenter works with
  A match is made if the ViewProvider finds a VaadinView annotated View whose name matches Presenter's viewName
  @return an implementor of {@link View}