code: public ResourceBundle getResourceBundle(Class<?> aClass, String bundleName, Locale locale) {
          return getResourceBundle(aClass, bundleName, (locale == null) ? null : Collections.singletonList(locale));
      }
docs: Like {@link #getResourceBundle(Class, String, List)}, but takes a single
  Locale.
  
  @see #getResourceBundle(Class, String, List)