code: public CmsUrlNameMappingFilter filterLocale(String locale) {
  
          if (locale == null) {
              throw new IllegalArgumentException();
          }
          CmsUrlNameMappingFilter result = new CmsUrlNameMappingFilter(this);
          result.m_locale = locale;
          return result;
      }
docs: Returns a new url name mapping filter based on the current one which also has to match a given locale.<p>
  
  @param locale the locale to match
  
  @return the new filter