@Test
  public void emptyQueryParam() throws URISyntaxException {
    UriComponentsBuilder builder = UriComponentsBuilder.newInstance();
    UriComponents result = builder.queryParam("baz").build();

    assertEquals("baz", result.getQuery());
    MultiValueMap<String, String> expectedQueryParams = new LinkedMultiValueMap<>(2);
    expectedQueryParams.add("baz", null);
    assertEquals(expectedQueryParams, result.getQueryParams());
  }