code: private void addSizeColumn() {
  
          Column<CmsHistoryResourceBean, ?> col = new TextColumn<CmsHistoryResourceBean>() {
  
              @Override
              public String getValue(CmsHistoryResourceBean historyRes) {
  
                  return "" + historyRes.getSize();
              }
          };
          addColumn(col, CmsHistoryMessages.columnSize());
          setColumnWidth(col, 100, Unit.PX);
      }
docs: Adds a table column.<p>