@Udf(description = "Returns a masked version of the input string. All characters of the input"
      + " will be replaced according to the default masking rules.")
  @SuppressWarnings("MethodMayBeStatic") // Invoked via reflection
  public String mask(
      @UdfParameter("input STRING to be masked") final String input
  ) {
    return doMask(new Masker(), input);
  }
@Test
  public void shouldApplyAllDefaultTypeMasks() {
    final String result = udf.mask("AbCd#$123xy Z");
    assertThat(result, is("XxXx--nnnxx-X"));
  }