private void compareToUDFDatetimeLegacyHybridCalendar(GenericUDF udf, long in, long out)
      throws HiveException {
    DateWritableV2 dateWInput = new DateWritableV2((int) in);
    DateWritableV2 dateWOutput = (DateWritableV2) udf
        .evaluate(new GenericUDF.DeferredObject[] {
            new GenericUDF.DeferredJavaObject(dateWInput)});
    Assert.assertEquals(dateWOutput.get(), Date.ofEpochDay((int) out));
  }
Input array is used to fill the entire specified size of the vector row batch.
ql/src/test/org/apache/hadoop/hive/ql/exec/vector/expressions/TestVectorUDFDatetimeLegacyHybridCalendar.java