UTF8Control and part of PlatformResourceBundleLocator.class

MessageInterpolator.java

private ResourceBundle loadBundle(ClassLoader classLoader, Locale locale, String message) {
    ResourceBundle rb = null;
    try {
            rb = ResourceBundle.getBundle(
                        bundleName, 
                        locale,
                        classLoader,
                        new UTF8Control());
        }
    catch ( MissingResourceException e ) {
        log.trace( message );
    }
    return rb;
}