@Override
    public void fromData(DataInput in,
        DeserializationContext context) throws IOException, ClassNotFoundException {
      throw new IOException("this fromData method should never be invoked");
    }
Chunker is used to send a VersionedObjectList to a client in pieces. It works by pretending to
be a VersionedObjectList during serialization and writing only a portion of the list in each
invocation of toData().
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/VersionedObjectList.java