@Udf
  public String ucase(
      @UdfParameter(description = "The string to upper-case") final String input) {
    if (input == null) {
      return null;
    }
    return input.toUpperCase();
  }
@Test
  public void shouldConvertToUpperCase() {
    final String result = udf.ucase("FoO bAr");
    assertThat(result, is("FOO BAR"));
  }