### Question:
DeliveryParameterBuilder { public DeliveryParameterBuilder language(String language) { if (language != null) { nameValuePairs.add(new NameValuePair(LANGUAGE, language)); } return this; }  static DeliveryParameterBuilder params(); DeliveryParameterBuilder filterEquals(String attribute, String value); DeliveryParameterBuilder filterLessThan(String attribute, String value); DeliveryParameterBuilder filterLessThanEquals(String attribute, String value); DeliveryParameterBuilder filterGreaterThan(String attribute, String value); DeliveryParameterBuilder filterGreaterThanEquals(String attribute, String value); DeliveryParameterBuilder filterRange(String attribute, String lower, String upper); DeliveryParameterBuilder filterIn(String attribute, String... values); DeliveryParameterBuilder filterIn(String attribute, Collection<String> values); DeliveryParameterBuilder filterContains(String attribute, String value); DeliveryParameterBuilder filterAny(String attribute, String... values); DeliveryParameterBuilder filterAny(String attribute, Collection<String> values); DeliveryParameterBuilder filterAll(String attribute, String... values); DeliveryParameterBuilder filterAll(String attribute, Collection<String> values); DeliveryParameterBuilder orderByAsc(String attribute); DeliveryParameterBuilder orderByDesc(String attribute); DeliveryParameterBuilder page(Integer skip, Integer limit); DeliveryParameterBuilder projection(String... elements); DeliveryParameterBuilder linkedItemsDepth(Integer depth); DeliveryParameterBuilder excludeLinkedItems(); DeliveryParameterBuilder language(String language); DeliveryParameterBuilder language(Locale language); DeliveryParameterBuilder includeTotalCount(); List<NameValuePair> build();  }### Answer:
@Test public void testLanguage() { List<NameValuePair> params = DeliveryParameterBuilder.params().language(Locale.US.toLanguageTag()).build(); Assert.assertEquals(1, params.size()); Assert.assertEquals("language", params.get(0).getName()); Assert.assertEquals("en-US", params.get(0).getValue()); }