docs: public void assertAtLeastOneDefined(final String param1, final String... moreParams) {
      if (!isPresent(param1)) {
        for (final String moreParam : moreParams) {
          if (isPresent(moreParam)) {
            return;
          }
        }
        final List<String> paramsForError = Lists.newArrayList();
        paramsForError.add(param1);
        paramsForError.addAll(Arrays.asList(moreParams));
        throw new ParameterException(
            String.format("At least one of %s must be defined.",
                StringUtils.CommaSpaceJoiner.join(paramsForError)));
      }
    }