public ConfigPayloadBuilder getObject(String name) {
        ConfigPayloadBuilder p = objectMap.get(name);
        if (p == null) {
            validateObject(name);
            p = new ConfigPayloadBuilder(getStructDef(name));
            objectMap.put(name, p);
        }
        return p;
    }
Get a new payload builder for a config struct, which can be used to add inner values to that struct.

@param name name of the struct to create
@return a payload builder corresponding to the name
config/src/main/java/com/yahoo/vespa/config/ConfigPayloadBuilder.java