@Udf(description = "Returns the inverse (arc) cosine of an INT value")
  public Double acos(
          @UdfParameter(
                  value = "value",
                  description = "The value to get the inverse cosine of."
          ) final Integer value
  ) {
    return acos(value == null ? null : value.doubleValue());
  }
@Test
  public void shouldHandlePositive() {
    assertThat(udf.acos(0.43), closeTo(1.1263035498590777, 0.000000000000001));
    assertThat(udf.acos(0.5), closeTo(1.0471975511965979, 0.000000000000001));
    assertThat(udf.acos(1.0), closeTo(0.0, 0.000000000000001));
    assertThat(udf.acos(1), closeTo(0.0, 0.000000000000001));
    assertThat(udf.acos(1L), closeTo(0.0, 0.000000000000001));
  }