code: public static <T> Set<T> wrap(final Set<T> source) {
          val list = new LinkedHashSet<T>();
          if (source != null && !source.isEmpty()) {
              list.addAll(source);
          }
          return list;
      }
docs: Wrap varargs.
  
  @param <T>    the type parameter
  @param source the source
  @return the set