void addNestedService(Service service)
    {
        if (nestedServices.put(service.name, service) != null)
        {
            throw err("Duplicate nested service: " +
                    service.name + " from message: " + name, getProto());
        }
    }
Represents the message defined in the {@link Proto}.

@author David Yu
@created Dec 19, 2009
protostuff-parser/src/main/java/io/protostuff/parser/Message.java