public Builder deployData(DeployData deployData) {
            this.metaData = Optional.of(metaDataFromDeployData(appDir, deployData));
            return this;
        }
Builder for {@link com.yahoo.config.model.application.provider.FilesApplicationPackage}. Use
this to create instances in a flexible manner.
config-application-package/src/main/java/com/yahoo/config/model/application/provider/FilesApplicationPackage.java