public static ObjectInspector getConvertedOI(
      ObjectInspector inputOI, ObjectInspector outputOI,
      Map<ObjectInspector, Boolean> oiSettableProperties
      ) {
    return getConvertedOI(inputOI, outputOI, oiSettableProperties, true);
  }
Returns a converter that converts objects from one OI to another OI. The
returned (converted) object belongs to this converter, so that it can be
reused across different calls.
serde/src/java/org/apache/hadoop/hive/serde2/objectinspector/ObjectInspectorConverters.java