@Udf(description = "Returns the base 10 logarithm of an INT value.")
  public Double log(
          @UdfParameter(
                  value = "value",
                  description = "the value get the base 10 logarithm of."
          ) final Integer value
  ) {
    return log(value == null ? null : value.doubleValue());
  }
@Test
  public void shouldHandleNull() {
    assertThat(udf.log((Integer)null), is(nullValue()));
    assertThat(udf.log((Long)null), is(nullValue()));
    assertThat(udf.log((Double)null), is(nullValue()));
    assertThat(udf.log(null, 13), is(nullValue()));
    assertThat(udf.log(null, 13L), is(nullValue()));
    assertThat(udf.log(null, 13.0), is(nullValue()));
    assertThat(udf.log(13, null), is(nullValue()));
    assertThat(udf.log(13L, null), is(nullValue()));
    assertThat(udf.log(13.0, null), is(nullValue()));
  }