private void copyUserDefsIntoApplication() {
        File destination = appSubDirs.configDefs();
        destination.mkdir();
        ConfigDefinitionDir defDir = new ConfigDefinitionDir(destination);
        // Copy the user's def files from components.
        List<Bundle> bundlesAdded = new ArrayList<>();
        for (Component component : getComponents(appSubDirs.root())) {
            Bundle bundle = component.getBundle();
            defDir.addConfigDefinitionsFromBundle(bundle, bundlesAdded);
            bundlesAdded.add(bundle);
        }
    }
Reads a ranking expression from file to a string and returns it.

@param name the name of the file to return,
            relative to the search definition directory in the application package
@return the content of a ranking expression file
@throws IllegalArgumentException if the file was not found or could not be read
config-application-package/src/main/java/com/yahoo/config/model/application/provider/FilesApplicationPackage.java