code: public static String getValueWithGlobalDefault(String section, ConfigConstant key) {
      String value = getValue(section, key);
      return (Strings.isNullOrEmpty(value) ? getGlobalValue(key) : value);
    }
docs: If the named section does not have the value, then try the same key from the "global" section
  
  @param section
  @param key
  @return