code: public FessMessages addErrorsFrontPrefix(String property) {
          assertPropertyNotNull(property);
          add(property, new UserMessage(ERRORS_front_prefix));
          return this;
      }
docs: Add the created action message for the key 'errors.front_prefix' with parameters.
  <pre>
  message: &lt;div class="alert alert-warning"&gt;
  </pre>
  @param property The property name for the message. (NotNull)
  @return this. (NotNull)