@staticmethod
def disconnect(controller_widget, control_name, control_instance):
    """ Disconnect an 'Enum' controller trait and an 'EnumControlWidget'
        controller widget control.

        Parameters
        ----------
        controller_widget: ControllerWidget (mandatory)
            a controller widget that contains the controller we want to update
        control_name: str(mandatory)
            the name of the controller widget control we want to synchronize
            with the controller
        control_instance: QComboBox (mandatory)
            the instance of the controller widget control we want to
            synchronize with the controller
        """
    widget_hook, controller_hook = control_instance._controller_connections
    controller_widget.controller.on_trait_change(controller_hook, name=
        control_name, remove=True)
    control_instance.activated.disconnect(widget_hook)
    del control_instance._controller_connections
