code: public String keyDefault(String keyName, String defaultValue) {
  
          String result = key(keyName, true);
          return (result == null) ? defaultValue : result;
      }
docs: Returns the localized resource string for a given message key.<p>
  
  If the key was not found in the bundle, the provided default value
  is returned.<p>
  
  @param keyName the key for the desired string
  @param defaultValue the default value in case the key does not exist in the bundle
  @return the resource string for the given key it it exists, or the given default if not