ate(int index, ContactInfo object, String value) {
        // Called when the user changes the value.
        object.setLastName(value);
        ContactDatabase.get().refreshDisplays();
      }
    });
    dataGrid.setColumnWidth(3, 20, Unit.PCT);

    // Age.
    ageColumn = new Column&lt;ContactInfo, Number&gt;(new NumberCell()) {
      @Override
      public Number getValue(ContactInfo object) {
        return object.getAge();
      }
    };
    ageColumn.setSortable(true);
    sortHandler.setComparator(