code: public Column addColumn(Grid grid, String label, String width, String sortBy) {
          Column column = new Column();
          grid.getColumns().addChild(column);
          column.setLabel(label);
          column.setWidth(width);
          column.setSortComparator(sortBy);
          column.setSortOrder(SortOrder.ASCENDING);
          return column;
      }
docs: Adds a column to a grid.
  
  @param grid Grid.
  @param label Label for column.
  @param width Width for column.
  @param sortBy Field for sorting.
  @return Newly created column.