@Test
  public void testVectorUDFYearString() throws HiveException {
    testVectorUDFYear(TestType.STRING_LONG);

    VectorizedRowBatch batch = getVectorizedRowBatchStringLong(new byte[] {'2', '2', '0', '1', '3'}, 1, 3);
    VectorExpression udf = new VectorUDFYearString(0, 1);
    udf.evaluate(batch);
    LongColumnVector lcv = (LongColumnVector) batch.cols[1];
    Assert.assertEquals(false, batch.cols[0].isNull[0]);
    Assert.assertEquals(true, lcv.isNull[0]);
  }
Input array is used to fill the entire size of the vector row batch
ql/src/test/org/apache/hadoop/hive/ql/exec/vector/expressions/TestVectorTimestampExpressions.java