@Override
  public void readFields(DataInput in) throws IOException {
    throw new UnsupportedOperationException("LazyHCatRecord is intended to wrap"
      + " an object/object inspector as a HCatRecord "
      + "- it does not need to be read from DataInput.");
  }
An implementation of HCatRecord that wraps an Object returned by a SerDe
and an ObjectInspector.  This delays deserialization of unused columns.
hcatalog/core/src/main/java/org/apache/hive/hcatalog/data/LazyHCatRecord.java