code: public void clear() {
          for (int i = cells.size() - 1; i >= 0; i--) {
              Cell<C, T> cell = cells.get(i);
              if (cell.widget != null)
                  toolkit.removeChild(table, cell.widget);
              toolkit.freeCell(cell);
          }
          cells.clear();
          rows = 0;
          columns = 0;
          if (rowDefaults != null)
              toolkit.freeCell(rowDefaults);
          rowDefaults = null;
          invalidate();
      }
docs: Removes all widgets and cells from the table.