code: public static JPopupMenu leftShift(JPopupMenu self, GString gstr) {
          self.add(gstr.toString());
          return self;
      }
docs: Overloads the left shift operator to provide an easy way to add
  components to a popupMenu.<p>
  
  @param self a JPopupMenu
  @param gstr a GString to be added to the popupMenu.
  @return same popupMenu, after the value was added to it.
  @since 1.6.4