code:     public void testWithVariantRequestOnly() throws Exception {
          params.put(I18nInterceptor.DEFAULT_REQUESTONLY_PARAMETER, "fr_CA_xx");
          interceptor.intercept(mai);
  
          assertNull(params.get(I18nInterceptor.DEFAULT_PARAMETER)); // should have been removed
          assertNull(session.get(I18nInterceptor.DEFAULT_SESSION_ATTRIBUTE));
  
          Locale variant = new Locale("fr", "CA", "xx");
          Locale locale = mai.getInvocationContext().getLocale();
          assertNotNull(locale); // should be stored here
          assertEquals(variant, locale);
          assertEquals("xx", locale.getVariant());
      }
  
      @Test
  