private void applyUserConfig(ConfigInstance.Builder builder, ConfigPayloadBuilder payloadBuilder) {
        ConfigInstance.Builder override;
        if (builder instanceof GenericConfig.GenericConfigBuilder) {
            // Means that the builder is unknown and that we should try to apply the payload without
            // the real builder
            override = getGenericConfigBuilderOverride((GenericConfig.GenericConfigBuilder) builder, payloadBuilder);
        } else {
            override = getConfigInstanceBuilderOverride(builder, ConfigPayload.fromBuilder(payloadBuilder));
        }
        ConfigInstanceUtil.setValues(builder, override);
    }
Sets the config id for this producer. Will also add this
service to the root node, so the new config id will be picked
up.  Note that this producer will be known with both the old
and the new config id in the root node after using this method.
config-model/src/main/java/com/yahoo/config/model/producer/AnyConfigProducer.java