MessagePackDeserializer-code.java

@MessagePackDeserializer(PlanNodeDeserializer.class)
public abstract class PlanNode
{
    ...
}

public class PlanNodeDeserializer extends Deserializer<PlanNode>
{
    public PlanNode deserialize(Unpacker unpacker)
    {
        Value value = unpacker.unpackValue();
        if (value.asMap().map().get("error") != null) {
            return new ObjectMapper().readValue(value, ErrorNode.class);
        } else if (value.asMap().map().get("engine") != null) {
            return new ObjectMapper().readValue(value, EngineNode.class);
        } else {
            throw new MessageTypeException("unknown type");
        }
    }
}