code: public static String markers(final List<String> markers) {
          String signs = "";
          if (markers != null && !markers.isEmpty()) {
              signs = "*" + Joiner.on(", ").join(markers);
          }
          return signs;
      }
docs: Renders markers as: *marker1,marker2..
  
  @param markers markers to render (may be null)
  @return rendered markers or empty string if no markers provided