docs: public static <T> Iterator<T> unique(Iterator<T> self, @ClosureParams(value=FromString.class, options={"T","T,T"}) Closure condition) {
          Comparator<T> comparator = condition.getMaximumNumberOfParameters() == 1
                  ? new OrderBy<T>(condition, true)
                  : new ClosureComparator<T>(condition);
          return unique(self, comparator);
      }