@Udf(description = "Returns the current number of days for the system since "
      + "1970-01-01 00:00:00 UTC/GMT.")
  public int unixDate() {
    return ((int) LocalDate.now().toEpochDay());
  }
@Test
  public void shouldReturnDays() {
    // When:
    final int result = udf.unixDate(new Date(864000000));

    // Then:
    assertThat(result, is(10));
  }