code: public static ErrorMessageFactory shouldBeSorted(int i, Object group) {
      List<?> groupAsList = groupAsList(group);
      return new ShouldBeSorted("group is not sorted because element %s:<%s> is not less or equal than element %s:<%s>.\n"
          + "group was:\n" + "<%s>", i, groupAsList.get(i), i + 1, groupAsList.get(i + 1), groupAsList);
    }
docs: Creates a new <code>{@link ShouldBeSorted}</code>.
  @param i the index of elements whose not naturally ordered with the next.
  @param group the actual group in the failed assertion (either collection or an array).
  @return an instance of {@code ErrorMessageFactory}.