docs: public void show() {
          if (!(container instanceof RootPanel)) {
              if (!(container instanceof MaterialDialog)) {
                  container.getElement().getStyle().setPosition(Style.Position.RELATIVE);
              }
              div.getElement().getStyle().setPosition(Style.Position.ABSOLUTE);
          }
          if (scrollDisabled) {
              RootPanel.get().getElement().getStyle().setOverflow(Style.Overflow.HIDDEN);
          }
          if (type == LoaderType.CIRCULAR) {
              div.setStyleName(CssName.VALIGN_WRAPPER + " " + CssName.LOADER_WRAPPER);
              div.add(preLoader);
          } else if (type == LoaderType.PROGRESS) {
              div.setStyleName(CssName.VALIGN_WRAPPER + " " + CssName.PROGRESS_WRAPPER);
              progress.getElement().getStyle().setProperty("margin", "auto");
              div.add(progress);
          }
          container.add(div);
      }