code: private void addPublishDateColumn() {
  
          addColumn(CmsHistoryMessages.columnPublishDate(), 190, new TextColumn<CmsHistoryResourceBean>() {
  
              @Override
              public String getValue(CmsHistoryResourceBean historyRes) {
  
                  if (historyRes.getPublishDate() != null) {
                      return historyRes.getPublishDate().getDateText();
                  }
                  return "-";
              }
          });
      }
docs: Adds a table column.<p>