CheckboxEditor and BooleanFormatter

CheckboxEditor and BolleanFormatter do no appear to work properly. I have the following code, but nothing displays in that column (regardless of true or false, selected or not). Other columns display fine, and are editable as expected. Am I doing something wrong or is tihs a bug?

columns_controls=[TableColumn(field=‘Test ID’, title=‘Test ID’,width=60),

TableColumn(field=‘Field’, title=‘Field’,editor=StringEditor()),

TableColumn(field=‘Length’, title=‘Length’,editor=CheckboxEditor(), formatter=BooleanFormatter(icon=‘check’)),

]

tab_controls=DataTable(height=“auto”, source=source_controls

,columns=columns_controls,fit_columns=True,editable=True)