Assuming this table can be part of a form (which I'm not sure it is, but if so), you may also want to provide a `fill` mechanism.

eg 
```py
web_ui.fill(mycheckbox_table, ["item1", "item2", "item3"])  # checks those 3 items
web_ui.fill(mycheckbox_table, CheckBoxTable.None)  # unchecks all
```