code: public static void fixDisplayedText(final RESTTextContentSpecV1 source) {
          if (source.getFailedContentSpec() != null) {
              source.setText(source.getFailedContentSpec());
          }
      }
docs: If the last save of the content spec was not valid, the text field will display the
  last valid state, the errors field will be populated, and the failedContentSpec will
  have the invalid spec text.
  
  In this situation, the UI will display the invalid spec text. So we copy the invalid text
  into the text field, and edit as usual. This provides a workflow much like topics where
  the user can save invalid data, and will receive a warning about it when the save is completed.
  
  @param source The spec to fix