@Udf
  public Long trunc(@UdfParameter final Long val) {
    return val;
  }
@Test
  public void shouldHandleNullValues() {
    assertThat(udf.trunc((Integer) null), is((Long) null));
    assertThat(udf.trunc((Long) null), is((Long) null));
    assertThat(udf.trunc((Double) null), is((Long) null));
    assertThat(udf.trunc((Double) null), is((Long) null));
    assertThat(udf.trunc((BigDecimal) null), is((BigDecimal) null));
    assertThat(udf.trunc((Double) null, 2), is((Long) null));
    assertThat(udf.trunc((BigDecimal) null, 2), is((BigDecimal) null));
  }