@Udf(description = "Returns the natural logarithm (base e) of an INT value.")
  public Double ln(
        @UdfParameter(
            value = "value",
            description = "the value get the natual logarithm of."
        ) final Integer value
  ) {
    return ln(value == null ? null : value.doubleValue());
  }
@Test
  public void shouldHandleZero() {
    assertThat(Double.isInfinite(udf.ln(0.0)), is(true));
  }