@Override
  public void fromData(DataInput in,
      DeserializationContext context) throws IOException, ClassNotFoundException {
    super.fromData(in, context);
    key = DataSerializer.readObject(in);
    cbArg = DataSerializer.readObject(in);
    this.context = DataSerializer.readObject(in);
    returnTombstones = in.readBoolean();
  }
Empty constructor to satisfy {@link DataSerializer} requirements
geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/GetMessage.java