protected void writeType(Type<?> type, DataOutput out) throws IOException {
    int slot = type.getSlot();
    out.write(slot);
    if (slot == 255) {
      out.writeUTF(type.getTargetName());
    }
  }
When writing out this instance, write down the canonical class name it proxifies.
@param out the output
@throws IOException if things go wrong
standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/properties/SerializationProxy.java