@Override
  public void readExternal(ObjectInput in) throws IOException {
    long serial = in.readLong();
    if (serial != serialVersionUID) {
      throw new ProxyException("invalid serial version, got " + serial +", expected " + serialVersionUID);
    }
    type = readType(in);
    proxied = type.proxyNew(in);
  }
Called by serialization after readExternal.
@return the proxied instance
@throws IOException for signature compliance
standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/properties/SerializationProxy.java