code: protected String getMessage(String contextId, String fieldPath, String[] faceDescriptorProperties,
              String defaultValue) {
          String[] keys = getMessageKeys(contextId, fieldPath, faceDescriptorProperties);
          try {
              return getMessageSourceAccessor().getMessage(new DefaultMessageSourceResolvable(keys, null, defaultValue));
          } catch (NoSuchMessageException e) {
              if (log.isDebugEnabled()) {
                  log.debug(e.getMessage());
              }
              return null;
          }
      }
docs: Returns the value of the required property of the FieldFace. Delegates to the getMessageKeys for the message key
  generation strategy.