code: public static HorizontalPanel newRow (HasAlignment.VerticalAlignmentConstant valign,
                                            String styleName, Widget... contents)
      {
          HorizontalPanel row = new HorizontalPanel();
          row.setVerticalAlignment(valign);
          if (styleName != null) {
              row.setStyleName(styleName);
          }
          for (Widget widget : contents) {
              if (widget != null) {
                  if (row.getWidgetCount() > 0) {
                      row.add(newShim(5, 5));
                  }
                  row.add(widget);
              }
          }
          return row;
      }
docs: Creates a row of widgets in a horizontal panel with a 5 pixel gap between them. The supplied
  style name is added to the container panel.