private void testCast(int typeCode, ObjectInspector inputOI, Object input, String format,
      String expOutput) throws HiveException {
    testCast(typeCode, 0, inputOI, input, format, expOutput);
  }
Tests CAST (<TIMESTAMP/DATE> AS STRING/CHAR/VARCHAR FORMAT <STRING>) and
CAST (<STRING/CHAR/VARCHAR> AS TIMESTAMP/DATE FORMAT <STRING>).
ql/src/test/org/apache/hadoop/hive/ql/udf/generic/TestGenericUDFCastFormat.java