code: public static QueryTemplate append(QueryTemplate queryTemplate,
                                       Iterable<String> values,
                                       CollectionFormat collectionFormat) {
      List<String> queryValues = new ArrayList<>(queryTemplate.getValues());
      queryValues.addAll(StreamSupport.stream(values.spliterator(), false)
          .filter(Util::isNotBlank)
          .collect(Collectors.toList()));
      return create(queryTemplate.getName(), queryValues, queryTemplate.getCharset(),
          collectionFormat);
    }
docs: Append a value to the Query Template.
  
  @param queryTemplate to append to.
  @param values to append.
  @return a new QueryTemplate with value appended.