code: public static ResourceBundle getBundle(ResourceBundle self, String bundleName, Locale locale) {
          Class c = ReflectionUtils.getCallingClass();
          ClassLoader targetCL = c != null ? c.getClassLoader() : null;
          if (targetCL == null) targetCL = ClassLoader.getSystemClassLoader();
          return ResourceBundle.getBundle(bundleName, locale, targetCL);
      }
docs: Works exactly like ResourceBundle.getBundle(String, Locale).  This is needed
  because the java method depends on a particular stack configuration that
  is not guaranteed in Groovy when calling the Java method.
  
  @param self       placeholder variable used by Groovy categories; ignored for default static methods
  @param bundleName the name of the bundle.
  @param locale     the specific locale
  @return the resource bundle
  @see java.util.ResourceBundle#getBundle(java.lang.String, java.util.Locale)
  @since 1.6.0